A young filmmaker Ihor finds a hidden and unpublished photo archive of his grandfather Leonid Burlaka, a famous Soviet cinematographer. Discovering a man that he never knew well enough through the damaged pictures, he gets closer to his dementing grandpa, facing the tension between memory and forgetting.

Imaginaerum tells the story of an elderly composer, Tom, who suffers from severe dementia. As he has had the disease for years and has regressed into childhood, he remembers practically nothing from his adult life. His music, friends, all his past including the memory of his daughter are a blur in his fragile mind. All he has left is the imagination of a ten year old boy. As he drifts away into coma, it seems impossible to get back what he has lost. Or is it?