The idea is that David, an ordinary guy, suddenly gets a message from his as yet unborn daughter from the future, Destroy the time machine that you are building or you will be killed. This he does but unfortunately now his daughter has no existence in the new time stream!
David realizes the mistake that he has made and now sets about trying to restore his daughter’s timeline at any cost. In the process he has to defeat those who are trying to rewrite history so that Nazi Germany can win the Second World War!
This book has everything from sadness and self sacrifice through to humor and sexuality and it pushes the envelope on all the traditional time travel paradoxes.
A great read and thoroughly recommended.