At the start of the series, the Second Earth Recapture Mission from the Mars Base is sent to invade an Inbit-dominated Earth. Hopes are high, the new soldiers are freshly trained, with new weapons and a will to win back the cradle of the human race. Their efforts meet with limited success, and their strike is utterly defeated leaving only a few scattered remnants. One of these remnants is a lone soldier named Stick Bernard, a man who is out for revenge against the Inbit. Armed with only a Ride Armor, a holographic recording of his dead fiance, and a scavenger named Rey he meets along the way, he begins his battle to destroy the Inbit.

Stick and his new partner Rey travel to an island city, entering despite several warnings from the cities ex-inhabitants. They meet a young girl named Mint who leads them to a neighboring island to look for other soldiers. Meanwhile, Stick and Rey's contact within the city conspires with the Inbit to provide their capture. The battle is hard, and it looks as though Stick, Rey, and Mint are done for. From out of nowhere a single red Ride Armor trooper appears and helps them fight off the Inbit Gruab Seconds. The Ride Armor trooper disappears as quickly as she came, and Stick and Rey discover that the people of this "Lost City" conspire with the Inbit in return for peace. Stick and Rey leave disgusted, and Mint joins the battle.

Stick, Rey, and Mint happen upon a frontier town, run-down by the constant wars and apathy. A famous singer is performing at a local club, and the group walks in on a rather heated criticism of her performance. The local riff-raff are restless, and have chosen the famous singing star Yellow to torment. A woman, a customer of the club, intervenes in the dispute, causing the wrath of the thugs to fall upon her. She is able to handle herself, and more importantly, her attackers. Stick notices it was she who rode the red painted Ride Armor and saved their lives in the previous episode. The thugs, dealing with their defeat by Stick, Rey, Mint, Yellow, and Houquet Eroze the Ride Armor rider decide to kidnap a local man. His friend, though he has a sordid past with Mars Base, decides to join forces with Stick's group to rescue his friend. The rescue operation is noticed by the Inbit, and Stick realizes that this deserter, named Jim Austin, has a lot to offer his makeshift team, most notably a well-armed and maintained Legioss Armo-fighter. Jim decides to join Stick's group, as does Houquet and Yellow, who reveals that she is actually a he named Yellow Belmont: a disguise meant to shroud his attacks on the Inbit.

The team is learning to live and fight together. Some people rub others the wrong way, especially Houquet and Rey. While getting supplies, Stick, Houquet, Mint, Rand, and Jim are ambushed by Inbit. Stick realizes that he needs the Legioss to battle this squad, but is afraid to indicate their campsite by making a straight line to the armo-fighter. Yellow Belmont patiently waits by the fighter while the rest of the group fight the Inbit. Rey reveals both his survival skill in the episode, along with his excellent reasoning. He catches fish and helps the group to deal with the horrors of the wild, namely leeches. He also discovers that the Inbit can sense the use of active military hardware. This enables the team to elude the Inbit by using only the minimum amount of energy. With the help of Yellow, Stick finally reaches the fighter and destroys the Inbit patrol that has been tailing them.

Stick's group of makeshift freedom fighters stages a raid on an Inbit HBT cell store to replenish their own supplies. This human-run Inbit reserve is drawn off-guard by a huge concert by the famous Yellow. Stick, Houquet, and Rey infiltrate the storage complex armed with rope and an ancient map of the building and it's secret passages. No plan is ever perfect, and Stick, Houquet and Rey find themselves locked in a sealed room, filling slowly with water. Eventually, they get out, but Yellow has postponed the end of her concert too long, causing the city guard to get nervous. When the robbery is discovered, the Inbit arrive. But with a replenished supply of fuel cells, Stick's group scores an easy victory.

Houquet withdraws from the group more and more, until she finally leaves during the night. Rey follows to see what she is up to. Stick knows that they left, but decides to let them go. Rey follows Houquet to a cavern that surrounds a city. Houquet is at home, through a series of flashbacks and conversations, and remembers why she left and the people that made her leave. Her days in a street gang haunt her, and she confronts the members of a rival gang who beat her severely. This episode is filled with excellent character development for Houquet, and some depth is added to Rey's character at the same time. Stick decides to look for Houquet and Rey, and ends up tangling with the Inbit. Once again, Houquet saves Stick from certain doom, and puts her abusers to shame at the same time. Rey helps Houquet to see her mother one last time, and they are on their way, and she makes a vow to herself to stay with the group of freedom fighters, who have become her family.

Stick's group of fighters continues on their journey to find the Inbit's main hive, making a stop in a small town at Jim's urging. Jim made a promise to a friend he had in his unit, who died in an Inbit attack during the First Earth Recapture Mission. His promise was to deliver a book to his friend's father who lives in this town. The group gets behind Jim's effort and his happy to spend a little time in a small town. Unfortunately, the townspeople don't feel the same way. The group begins to notice that the townspeople are giving them the runaround. Eventually, after some of the group gets kidnapped, Jim forces an explanation out of the mayor. It turns out that the father of Jim's friend tried to keep the townspeople out of the war with the Inbit. He wanted them to leave the fighting to the soldiers. The townspeople wouldn't stand for the interference. In the end, they killed the peacemaker. Jim is disappointed, and ends the episode in a melancholy mood. He decides to keep the book to remember some of the things that the father of his friend stood for.

The group comes to a settlement of soldiers led by the legendary Colonel Jonathan, leader of the famous Mars Base Angel Fang unit. It is not a military outpost, but rather a safe place where they come and relax. Apparently, the Inbit leave the city alone due to the number of soldiers encamped there. In Stick's dealings with the Inbit, he had seen no such fear. He doubts the party mentality of the town. But Stick awe of his hero is greater and agrees to go along on one of Jonathan's missions and is ambushed. Rey and Houquet confront a returned Johnson about what happened to Stick, and he agrees to take them to look him. Quickly they are ambushed by the Inbit, but Houquet arrives in a nick of time to save Rey, only for the pair to be forced to split up. Rey stumbles upon a meeting between a humanoid style Inbit and Jonathan, where the war hero receives some HBT cells. Rey realizes the connection, Jonathan trades his soldiers for the fuel, coming back a hero every time. Upon confronting him, Jonathan tries to justify his actions as keeping the civilian population safe. Stick is found alive and well, and is none to happy to listen to Rey's story. As the Inbit attack again, Jonathan sees Stick is alive and learns that he was betraying those who believed in him. He borrows the group's Legioss and quickly defeats the aliens, but not before he is mortally wounded. He sees the error of his ways just before he dies in Stick's arms.

While scouting out a new campsite, Stick, Rey, and Mint fall into one of the Invid leader's "Genesis Pits" where she is doing strange experiments. Dinosaurs, monsters, Invid, and possession are all part of the evolutionary experiments conducted by the Inbit leader, the Refles. Rey figures that the Refles is trying to figure out what the dominant species on Earth is and how she can exploit it. Stick and Rey find out, through the Refles' possession of Mint, that the Refles plans to exterminate the humans in favor of the Inbit's ultimate life form.

The rag-tag group of freedom fighters arrive at the fallback point of the Mars Base Recapture Missions. Unfortunately, the Inbit had arrived earlier and all that remains the invasion force is only a scattered hulks and corpse of ships, mecha and men. Stick was counting on this group is shocked and begins to lose hope in the mission. While on a scouting mission, Houquet and Rey find a naked woman who appears to be a battle survivor. In actuality, she is an agent of the Inbit Refles, engineered to spy on the freedom fighters. Houquet and Rey take her back to their camp. Yellow and Jim find several new fighters to add to their arsenal, and get to try them out against an Inbit patrol. Stick realizes that others are relying on him and enters into battle, destroying the Inbit patrol.

A mountain range lies between Stick's group and Reflex Point, a mountain range with an Inbit base right in the middle of it. The group finds that there is a "secret route" through the mountains, but the map that indicates it costs quite a bit of money. Stick's group reluctantly looks for ways to make money. Yellow Belmont has a brush with his past, and we find out why he dresses up like a woman. His lost love is the fiance of the seller of the map, and she tells Yellow that the maps are fakes. There is more human betrayal in this episode, along with some brushes with death. In the end, Yellow's lost love stays with her fiance, and Yellow and the rest of the group trudge on to Reflex Point.

After receiving a real map of the mountains, the rebels find that the only way through the range is through the Inbit. Stick devises a strategy to attack the base, with some very useful help from Rey. Rey and Mint sneak into the base, and attempt to knock out their energy detector. Stick orders everyone out of the base while he single-handedly destroys the base and the Inbit troopers.

While camping inside a cave during a sandstorm, the group begins to bicker. Rey ends up being the object of everybody's anger because he gives water to Aisha that no one knew he had. Rey takes the criticism poorly and braves the sandstorm to find more water. Unfortunately, the sandstorm blinds Rey and he falls into a sand pit and has a hallucinatory dream. He gains insight into the Inbit's plans of the domination of the universe. Aisha is Rey's guide through his hallucinatory adventure, but Rey doesn't make the connection between the Inbit and Aisha.

The journey to Reflex Point takes Stick's group through a jungle near a giant Inbit stilt hive. This jungle is inhabited by a primitive tribe of people who worship the gods of the river, and believe that the rebel group has angered the river god. Meanwhile, the Refles creates a new type of Inbit mecha meant to provide heavy resistance to the Earth people. She begins to deploy the prototypes in an effort to attack the freedom fighters. The rebel band helps the river tribe defeat an Inbit patrol and please their river god. They then slip under a huge Inbit hive in rafts. This saves immeasurably on energy cells and keeps the Inbit from detecting their energy use. However, the freedom fighters are in low spirits after leaving Mint behind to marry McGruder, a tribal prince.

In a devastated city, Stick's group is driven into the subway by the Refles' new mecha, the Gamo. What's more, they are sealed inside a small section of subway by the Refles' constant effort at their destruction. The Refles is not sure that the freedom fighters are dead, so she orders her Iigaa's to dig through the rubble. Tensions run high with the buried alive, what with the recent loss of Mint. Jim snaps and starts fights with both Rey and Stick. Jim's blow-up causes several people to think, especially Rey and Houquet. They decide to leave the group together, in hopes to find more people and possibly provide a little rest and relaxation for the group. However, deep down they both know that when they leave they are never coming back. Eventually, Rey engineers a nifty little escape, and the group escapes their would-be tomb. To their surprise, Mint is waiting for them near the other vehicles. The group is happy, but Rey and Houquet still decide to leave. Jim, Yellow, Aisha, and Mint decide to stay with Stick and keep fighting the Inbit. At the last moment, Houquet and Rey turn back and rejoin the group. The ordeal meant to split apart the group ended up unifying it, and Reflex Point is not far away.

The group of freedom fighters are at the northern tip of what was once called "South America." They devise a plan to cross the body of water between the two continents, using old gasoline driven ships that they found mothballed in a local shipyard. The rebels busy themselves with their preparation for the crossing. The Refles is also busy. She has finally found the perfect life form to dominate the Earth: the human being. She immediately creates a Solugi (humanoid inbit) prince and princess of the Inbit named Batra and Sorji, respectively. The Refles sends her children to combat the rebels that have corrupted her secret agent, Aisha the female who the group has adopted and has no memory of her past. . However, Sorji has similar problems to the lost secret agent. Human emotions are her downfall, and cause her to hesitate when it comes to destroying Yellow. The beginnings of love occur between Sorji and Yellow Belmont. Eventually, the rebels' cunning and courage fight off the Inbit and they make it to the northern continent.

After crossing the Gulf of Mexico, the freedom fighters find themselves in a snowy mountain range. Thinking that they have eluded the Inbit for the time being, Stick's group is in high spirits, joking and eating one of their few decent meals. They do not realize yet that Aisha is an Inbit, and that the Refles is using her to track the rebels. Unfortunately for the group, Sorji also finds herself and her gurab seconds in the mountain range, stalking the rebels. She is desperate to make up for her hesitation earlier, but finds that she cannot hurt the rebel known as "Yellow." She orders her troops to attack the group, and orients herself on the leader of the group. The sudden attack splits up the group, separating them from their mecha. Their only hope is to utilize their snowy surroundings against the Inbit. Sorji confronts Aisha for the first time, and the Refles telepathically tries to bring her child back to the hive. However, she is unsuccessful, and Sorji is surprised by the appearance of the other freedom fighters. Stick's group moves on, Aisha trying to forget the strange experience, and Yellow quite a bit suspicious of the Inbit pilot, it almost seemed she knew Aisha.

From the mountains to the desert. A few small towns are eking out a meager existence in the shadow of a huge Inbit transmission tower. Stick and the other rebels, still on their journey to Reflex Point, must find a way around or through the Inbit hive. Unfortunately, some members of the group have other things to deal with as well. Stick and Rey are captured by a local police force, and a local thief force steals their Ride Armors. Yellow and Aisha are taken in by some equipment wholesalers who just happen to be comrades of the thieves who stole Stick and Rey's Ride Armor.

Out of the desert, and back into the mountains. The cold has dowsed the spirits of the freedom fighters, just as the constant fighting has. Luckily, while passing through a high mountain pass, Rey finds a huge city buried under an ice canopy. The city provides both an escape from the cold and an escape for the war with the Inbit. The group splits up and enjoys the lost city, which they discover was called Denver. Stick and Aisha find that they have a great attraction between them and Rey and Houquet find that whatever is between them is something bordering on hate. Mint is in heaven, she finds a new dress and a whole stockpile of peppermint candy. Jim and Yellow discuss the current trend in Inbit mecha, how they keep getting better and better.

The rebels are forced to sneak around a deserted town while Mint mourns her destroyed birthday plans. Batra is near, and is easily tricked into retreat by a gadget of Yellow's. Stick and the others use the break in the Inbit threat to throw a birthday party for Mint. Mint gets everything she ever wanted: a cake, a big jar of peppermints, a new dress, a fireworks and airplane show, and most of all, she has a family. And although she would never admit it, that is exactly what she wanted. This celebration is hardly just a gift for Mint. It was also a welcome bonding opportunity for the group.

The gang is close to Reflex Point, but they have to deal with a local problem first. A seeming madman is killing all of the soldiers in the sector, and Stick's group vows to end his killing spree. However, after Houquet and Rey have a run in with a mysterious man called Rainy Boy, they begin to doubt the legend of the random killer. The posse assembled to bring down Rainy Boy brings also the wrath of the Inbit, and Stick's group see the awesome power of the Inbit, and how lucky they are to have gotten so far. Houquet convinces Rainy of the error of his mission and he dies while saving his new friend. Conversation with Rainy Boy provides insight into his psychosis, and also insight into the limits of human friendship. The group presses on. They can feel how close they are to Reflex Point.

Stick's rebel group is only a day or two away from Reflex Point, but they are badly in need of energy. They stop off in the remnants of New York City. Posing as homeless people, Rey, Yellow Belmont, and Mint find the local Inbit energy cell storage. The group decides to steal some energy cells. Unfortunately, Mint drops some hydrogen canisters, alerting the Inbit to their presence. They are only saved by a would-be actor, who convinces the Inbit that a stray cat was the cause of the commotion. Meanwhile, under pressure from the Refles, Batra decides to destroy all of the inhabitants of New York City. Sorji tries to stop him, but decides to use the situation as a chance to speak with Aisha. Again Aisha refuses to acknowledge that she is an Inbit.

As the title says, the freedom finally reaches Reflex Point, ready for their assault. However, they are a little late for the assault. An advance force from the Third Earth Recapture Mission had attacked earlier, and by the time Stick's group arrived, they had already been defeated. The ground around Reflex Point is littered with both destroyed Inbit and Mars Base mecha. At first, there are no survivors. Suddenly, a single Ride Armor rider appears, carrying a camera where her gun should be. She is Sue Graham, assigned to document the battles with the Inbit. Stick's group is horrified to find out that she filmed her comrades' destruction without lifting a finger to help them. Eventually, she seems to come around, and proposes a plan to fight the Inbit. Stick realizes that her plan to destroy the Inbit is actually just a plan to get some great camera footage of more Mars Base mecha being destroyed. The freedom fighters surprise her, and come out of the battle as victors. During the battle, Graham is mortally wounded. She dies after realizing her mistakes. Sue Graham is not the only casualty. During the battle, Aisha receives a cut on her arm. Where red blood should be flowing, only green blood appears. At that moment, standing next to an Inbit Solugi bleeding green blood, Aisha and the rest of the group realizes her true identity. Aisha runs off crying, and the others stand and watch, wondering if they will ever see her again.

The battle for the Earth begins. Ground troops from the newly arrived human forces have linked up with Stick's band of freedom fighters. Jim has been reinstated in military. All is ready for the attack. A lot happens during this episode. During the fight, Rey professes his love for Houquet, which she returns. Yellow's Legioss is hit by an Inbit energy bolt, and is saved from destruction by Sorji. The rebels are led to the Refles by Aisha, and the Refles explains her plans. The episode ends with Stick vowing to destroy Batra, and the others are left inside Reflex Point with the Refles.

The final episode of MOSPEADA picks up where the last left off. Stick is fighting Batra, and is shot down. Meanwhile, Houquet and Rey climb in their Legioss's, and decide to help Stick out. Jim and Mint vacate the battle scene, Jim is a ground fighter, and the ground attack is over. The Refles decides to leave the Earth, and take her children with her. Yellow agrees to help Sorji fight off the attacks until the Refles can leave. Stick finds his TREAD Armo-Bomber, and destroys Batra. The Refles leaves in a ball of fire, destroying the remaining Mars Base forces left in orbit. Yellow stages a concert, in which he reveals his true identity. Sorji was left behind, and she is at the concert to cheer Yellow on. Houquet and Rey leave to start their lives together. Jim, Mint, and Aisha drive off to start a farm. Stick flies back into space to return to Mars Base.