Based on

Movies like The Caveman's Valentine (2001)

Romulus, a misunderstood musician turned recluse hiding from personal demons in a New York City cave, finds the frozen body of a young drifter in a tree. The authorities, including his police officer daughter, claim the death is accidental. Romulus is convinced the man was murdered by a prominent art photographer but how can he prove he's right when everyone thinks he's insane?