In Duncan Jones’ Source Code, Air force pilot Colter Stevens (Jake Gyllenhaal) has to work out who bombed a train but only has the same eight-minute period to live through each time, a bit like Murder on the Orient Express if Poirot was knifed in the chest at the end of every chapter.

That concept — an individual living through a constrained period of time again and again while retaining all their memories — has been explored many times, not just in genre fiction (Star Trek‘s TNG episode Cause and Effect for instance) but in mainstream hits like Groundhog Day. That concept is a double-edged sword; as a narrative conceit it usually allows for an interesting story, but showing the same scenes again and again can drag upon the viewer — Cause and Effect runs out of steam about two-thirds of the way through, for instance.

With only eight minutes to play with, and each period ending in a fuck-off explosion, Source Code plays like a hyper-charged episode of Quantum Leap which helps stave off familiarity. Jones also keeps the repeating scenes tense by making the mission a race against time — the bomber must be found in the past before he or she can bomb again in the future. Even though the audience knows what’s going to happen at minute eight, the preceding minutes are different every time. Also, on a personal scale we’re as much in the dark as Stevens is. The train bomb, it turns out, isn’t the important part of the story: it’s just the background to Stevens’ own mystery about his involvement in the Source Code project and why his support team are so cagey.

Coming after the exceptional Moon, Source Code can feel a little unremarkable in comparison but it would be unfair to criticise it for this: it’s still a solid SF thriller and Gyllenhaal puts in a standout performance, striving to understand and complete his mission without letting his own reality get in the way. The supporting cast — Vera Farmiga, Jeffrey Wright and Michelle Monaghan — don’t disappoint.

Only the film’s ending felt like a misstep to me, feeling tagged on, and the one part of the film that probably won’t stand up to much scrutiny. That one niggle aside, Source Code is excellent, and Duncan Jones remains one to watch.