Synopsis of "The Flash" Film

After helping Bruce Wayne / Batman and Diana Prince / Wonder Woman stop a robbery in Gotham City, Barry Allen revisits his childhood home, where he lived with his parents Nora and Henry, before Henry's wrongful imprisonment for Nora's murder. On the day of her death, Nora sent Henry to the grocery store for a can of tomatoes that she forgot to buy, leaving her alone in the kitchen, resulting in her being killed by an unidentified assailant. Overcome by emotions, Barry accidentally uses the Speed Force to form a "Chronobowl" and travel back in time earlier in the day. Despite Bruce's warnings of time travel's unintended consequences, Barry time travels and places the can of tomatoes in Nora's cart at the store, so that his father will not have to leave the house... (Source: Wikipedia)