As a romance between a madman and the woman who idolized him and loved him and never left him, even after his descent into illness, it's wrenching. As a thriller about Nash's secretive work for the government and its shadowy operatives, it's captivating. And in the end, it's a film about which one doesn't want to say too much; it plays almost like The Sixth Sense, in a way, where things seen aren't always to be believed. To decipher them here would ruin the ambiguity, spoil the romance and dull the ache. What could well have been a lachrymose exercise, of the sort Howard's known for fashioning, is instead as haunting and long-lasting as a reverie -- or a hallucination, perhaps. Appropriate, indeed.