Let us first, then, look at the meat. Source Code's story, and the concept behind it, is generally pretty good. Captain Colter Stevens (Jake Gyllenhaal) awakens on a train unaware of how he got there sitting opposite a woman who knows him as Sean Fentress. Colter soon discovers that his reflection is that of someone else, but before he is able to find out anything further, the train explodes. Colter then wakes up strapped into a dark capsule, where he discovers from Captain Colleen Goodwin (Vera Farmiga) that the crash he just experienced happened earlier that day, and that he is part of an experimental military operation known as "Source Code". Colter's consciousness was transported into that of a passenger's - Sean's - for the final eight minutes of his life, with the aim of Colter discovering who is responsible for blowing up the train in order to avert further attacks in the future.
So far, so complex. But Duncan Jones' direction from the outset keeps things moving at a pleasing and steady pace whilst at the same time making the whole thing believable. You feel that Jones really hits his stride when depicting Colter's experiences outside of his transportation to the same eight minutes on the train. The design and nature of the bleak capsule Colter inhabits, with its harsh structural features and intrusive video and computer screens, has strong echoes of Gilliam's post-apocalyptic world Bruce Willis experiences in 1995's Twelve Monkeys. In fact, Jones' influence from a wide range of science fiction and beyond - from Inception to Groundhog Day - is apparent throughout Source Code, and the film is all the stronger for it. The director takes inspiration from respected sources, whilst at the same time crafting a fantastical concept that is original and fresh. Jones' first feature, the highly acclaimed Moon, is one that has so far (shamefully) passed me by, but on the strength of his handling of many elements on show here I feel all the more compelled to seek it out sooner rather than later.
Gyllenhaal too must not be undersold. His performance as the former army helicopter pilot thrown into a disorienting and perplexing scenario of which he has no recollection of choosing to be a part, shows diversity that perhaps has only been hinted at before. His previous roles, from romantic drama in Brokeback Mountain to action hero in Prince Of Persia, come together in his portrayal of Colter to provide a satisfying and genuine mix of humour, tension and pugnacity.
The supporting cast also do well, with both Farmiga as Captain Goodwin and Jeffrey Wright as Dr. Rutledge, the creator of the Source Code program, giving strong and memorable turns. Farmiga and Wright are key to the success of the darker and more mysterious aspects of the film; Wright's continuous use of a single crutch providing a unnerving quirk to his character. It is Goodwin's appearances on Colter's video screens that provide some of the film's most enduring sequences, however; the extreme close ups on Farmiga's face make her presence intrusive on both Colter and the audience, and the methods she uses to help bring the disoriented soldier back from his trips to the exploding train - asking him to recall series of cards from a story, playing bird calls into his capsule - have an unsettlingly sinister psychological edge to them.
Unfortunately, whilst there's a lot to like about Source Code, this is largely where the good stuff comes to an end. Michelle Monaghan is fine enough, if somewhat forgettable, in her role as Christina, Colter's perpetual travelling partner on the train. But the fact that her character, other than sharing some wonderfully shot slow-mo explosion scenes with Gyllenhaal, never feels anything much more than peripheral in the film as a whole means that the romantic thread between Christina and Colter largely falls flat.
The biggest failing, however, is the film's handling of the human side of its story. Whilst it's hard to address this without giving away large chunks of the story it's fair to say that, whilst Gyllenhaal makes his character sympathetic, many of the more emotional elements of his story regularly slip too far into melodrama and become swamped in pathos. As more and more about Colter's circumstances in reality (as opposed to on the train) is revealed, this becomes more and more of a problem. The second half of the film also has an ill-fitting anti-war undertone with more than a hint of schmaltzy Americana, which simply feels stale and tacked onto the science-fiction premise at the core of the film.
Ultimately, as stated previously, there really is a lot to enjoy within Source Code. Its sci-fi credentials are solid, and whilst it never reaches the heights of Nolan's Inception, it sits pleasingly a few steps below in the ranks of the cerebral blockbuster. In the end, however, Source Code leaves you feeling as though it never quite fully realises the potential that its concept holds. A little less preoccupation with pushing a message onto the audience, and a little more focus on both the darker mystery-thriller aspects that work so well throughout the film and the ingenious science-fiction concept at its nucleus, and this could have been an excellent film. As it is, the flaws are there, and noticeable enough to make it just very good.