Veille sur moi is the story of Maggie (Guylaine Tremblay) and her grandson Zack (Jérôme Hébert), whom she has been taking care of alone for three years, ever since her daughter Corinne (Pascale Renaud-Hébert) entrusted the child to her by disappearing into the fog with Joey (Guillaume Laurin), her toxic partner. But one afternoon, Zack and Maggie see their daily lives completely turned upside down when Corinne returns, now sober and separated from Joey, with the desire to pull herself together and take care of her son. This return, as much feared as desired, will have serious consequences.