What's it about? Jake Gyllenhaal time-travels through the same 8 minutes again and again in order to find out who bombed a train. Or does he?

Is it any good? Time and time again, we've seen this concept explored, but thankfully director Duncan Jones appreciates that good sci-fi is about stimulating the emotions as well as the mind, and delivers a worthy follow-up to Moon, helped along by nice performances all round. Although I would have preferred it finished about 5 mins earlier (you'll know the bit when you see it) and Gyllenhaal's character really should have been called Major Tom. Otherwise, very good.