As far as time loop films go, this is one of the better ones. Ultimately, these concept films stand or fall on how well they manage to package the many repetitions of such a loop in a varied way. Director Duncan Jones shows in the first act that he has learnt from his genre predecessors. Once the basic eight-minute loop on board a train has been established and the audience has understood the premise, each new repetition is used very attractively and skilfully to emphasise individual details. The variation of familiar scenes, very strongly played by Jake Gyllenhaal and especially Michelle Monaghan, is snappy and even invites you to in the puzzling: Which detail, which person, which object could become more important in the next round?

The little nods to the TV series Quantum Leap are very funny and a nice touch, even Scott Bakula has a small, almost invisible guest appearance. Source Code clearly follows the cerebral sci-fi cinema of its time and attempts to mix a conceptually ingenious vision of the future with sentimental character drama in a similar way to films such as Surrogates or Inception. Most of the time, this works very well, only in the last ten minutes does Jones oversteer into kitschy territory and tries to force a happy ending that breaks the previously established narrative rules - for which he drifts off into quantum physics and hocus-pocus dimensional portals.

It's too much wibbly wobbly timey wimey ... stuff at the end, but until then, Source Code is an enjoyable and fast-paced thriller.