The premise of Contact is a very simple one. A successful businessman in his fifties is approached by a young man who claims to be his son from an affair that he had thirty years earlier, an affair that he never told his wife about. There's no complicated plot; it's all about the interaction between the two men, the one comfortable and hitherto smug, the other full of barely-suppressed violence.
What gives the book its edge is the complete plausibility of the writing. The characters are entirely convincing and the reader, while seeing the story from the point of view of the businessman, nevertheless comes to empathise with the damaged, dangerous but proud young man who wants to be acknowledged as a member of the family.
The only criticism I have of the book is that nothing is resolved at the end. It's a realistic conclusion but not an emotionally satisfying one. Despite this I found this an utterly engrossing read - the sort of book that makes you miss your stop on the tube.