Safety Not Guaranteed is the latest film in that grand tradition, incorporating elements of the romance and longing in Richard Matheson’s novel Bid Time Return (filmed as Somewhere In Time in 1980), and perhaps even a dash of the 1960 film adaptation of The Time Machine in its production design. Although Jeff’s confident that the anonymous classified ad writer’s just another deluded soul to write an amusing story about, Darius is more credulous. Following an address in the advert, the trio discover the mysterious writer: 30-something Kenneth (Mark Duplass), who drives a battered Datsun, wears a denim jacket, and takes his combat and survival training very, very seriously. Jeff, less interested in the story and more intent on tracking down an old flame he’s rediscovered on Facebook, believes his worst suspicions are confirmed. But Darius decides to do dig a little deeper, and in attempting to discover whether Kenneth’s supposed time machine is real, finds herself increasingly drawn into the eccentric’s private world. Karan Soni gets some of the script’s very best lines (his reflection that Star Wars Stormtroopers are “blue collar workers” and would therefore know nothing of lasers is spectacularly written), and it’s arguable that Arnau and Jeff are one of the most entertaining odd couples to grace a cinema screen all year. Aubrey Plaza, already well-known for her performance as April in Parks And Recreation, is superb in the lead role, and Safety Not Guaranteed is a great showcase for her talent. She has a particular way of holding the screen – a dry charisma that’s filled with humour and quiet introspection. She and Mark Duplass have a strong chemistry, and the way their guarded personalities are gradually replaced by warmth and friendship is part of what makes the film so engaging. More than a mystery or a sci-fi film, though, Safety Not Guaranteed is primarily a romance, shot through with plenty of wry comedy. Mainstream romances have often floundered in either saccharin or worldly cynicism, but Trevorrow and Connolly are unafraid to depict the frailties of their characters. Plaza and Duplass aren’t your typical Hollywood leading couple, and all the better for it; their bittersweet childhood memories, the things in their past they desperately want to change, or hold onto, are things anyone can relate to – which is surely what we’re all looking for in a good movie. Anyone who keeps up with movie news will know that Safety Not Guaranteed has been a hit at movie festivals, and that its writer and director are planning a remake of another time-travel story, Flight Of The Navigator – Colin Trevorrow was even linked to the forthcoming Star Wars sequel at one point. It’s easy to see what the fuss is all about. Safety Not Guaranteed, on a relatively miniscule budget, is a lightweight yet effortlessly beguiling blending of genres. Its performances are touching, its dialogue sparkling, its lack of cynicism utterly refreshing. Safety Not Guaranteed is out in UK cinemas on the 26th December. Follow our Twitter feed for faster news and bad jokes right here. And be our Facebook chum here.