Dark Matter by Blake Crouch

I have to say up front that I didn't understand the science but was intrigued by the concept. Jason loves his wife and his life and goes out on evening to meet a friend only to wake up to a nightmare where his life is not his own and he is someone he does not know. He breaks out and travels in a time machine of his own design only to pop into various alternative realities. His alter ego is already taking over his life and now Jason must risk everything to get rid of the imposters and get his family back. Doorways leading to one nightmare after another await Jason. This thrill ride is full of scientific twists and turns no one can predict. After all, how do you fight for what you had when the person you are fighting is yourself? Bourne Identity meets Terminator - all Jason wants is his real life back. This thrill ride will have you questioning that feeling of deja vous.