As a game with possibly the most ridiculous and difficult-to-explain premise of any driving game in history, Driver: San Francisco has a lot to prove. It's difficult to see how a racer in which you can zoom out of your own body and temporarily inhabit any car in the road like a thrill-seeking poltergeist is actually going to work. Happily, Driver: SF brings you around to its way of thinking within minutes of picking up the controller. After spending half an hour or so playing around with the Shift system, you completely understand it – and you begin to see just how many new possibilities it opens up. Driver: SF sees the return of undercover cop John Tanner and his incarcerated arch-nemesis Jericho, who breaks out of prison and puts Tanner into a coma at the very beginning of the game. From then on, events take place inside Tanner's head, which explains how he's suddenly able to possess innocent denizens of San Francisco on their daily commute to work. After an hour or two, it becomes apparent that there's more to shifting than meets the eye, and it completely changes how you think about racing. Instead of concentrating purely on driving fast and cornering smartly, you can suddenly send oncoming traffic zooming into opponents to take them out, or block routes with a truck, or traverse the entire city in seconds. The handling is pretty hand-brake heavy and over the top and there are plenty of things to crash into, and though that's great fun when you're in a chase, it's not so fun when you're trying to beat a time.