The Peripheral - William Gibson
It never crossed Flynne Fisher’s mind that doing a favor for her brother would lead to such upheaval. After all, she was just doing security for some online game – or so she thought. This game was different, though: for one thing, the setting was… disturbingly familiar… and it was more realistic than any game she’d played before – especially the gruesome murder she witnessed. Flash forward a couple of days: word on the street is that there’s a contract out on her brother because someone thinks he saw something he shouldn’t have. What’s weird, though, is that the company who’d originally hired him is coming to his (and Flynne’s) defense with some pretty advanced tech. Turns out that her virtual reality trip hadn’t been into a game, it had been to the future. Or more accurately, to a future – you know: time-travel paradoxes and all that.