Mr. Harper is a telepathic mind living in a mind-blind world. He tends to keep his thoughts to himself except when he can't resist turning fugitives over to the police and succouring dying strangers by the side of the road. His penchant for amateur sleuthing lands him in trouble - he's tracking down some suspicious characters when he encounters a mind that is not as it should be.
Invasion of the Body Snatchers! This might sound derivative but only because it's been copied so many times.
Harper's perspective as a telepathic narrator is unique, but his path is too smooth to make this an interesting read. A sweet ending, though.