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?

Matthew, a young advertising executive in Chicago, puts his life and a business trip to China on hold when he thinks he sees Lisa, the love of his life who left him without a word two years earlier, walking out of a restaurant one day.

Horror novelist Luke Sinclair retreats to a small town to finish writing his latest book. A young woman is murdered in the woods nearby, in circumstances similar to those in his bestselling novel, “Reaper”. Faced with increasing pressure from a suspicious local sheriff, as well as the advances of a female FBI investigator, he must uncover the killer before he or she strikes again, further implicating him in the crime.