Clay McLeod Chapman 
Origins #2 [PDF ebook] 

Nowhere is safe on the planet that David helped destroy, including the secret hideout where he was brought back to life as the last living human. When enemy AI attacks, David and his robot guardian, Chloe, must face an impossible mission in search of answers. It’s a dangerous journey but humanity’s only hope lies in the father of robotics going back to where it all started – no matter the cost.