Book Club to New Worlds - Dark Matter by Blake Crouch

Science fiction: One night after an evening out, Jason Dessen, 40-year-old physics professor living with his wife and son in Chicago, is kidnapped at gunpoint by a masked man, driven to an abandoned industrial site and injected with a powerful drug. As he wakes, his life is not the one he knows. His wife is not his wife; his son was never born; and he's not an ordinary college professor, but a celebrated genius who has achieved something impossible. Is it this world or the other that's the dream? How can he possibly make it back to the family he loves?