The Shrinking Man by Richard Matheson. You may have seen the classic sci-fi movie " The incredible shrinking man" based on the book, memorable mainly for his escape from the pet cat and his titanic battle with a spider. I found the book in a charity shop and it has a much darker tone, whilst still a horror-adventure story, It's more a study of loss of masculinity. When he's down to 4ft he struggles to make love to his wife, he also attracts the attention of a paedophile.. . . . . It's an interesting read, worth picking up if you ever come across it.