Ah, the road trip movie.

It’s a genre that doesn’t get a lot of play in the United Kingdom, which isn’t surprising when you can drive its length in less than 24 hours. However as Black Dog handily demonstrates there still plenty of mileage in the British road trip when your interior is packed with dynamic and empathetic characters.

Our passengers for this journey consist of two mismatched Londoners heading North for separate reasons. Rambunctious foster teen Nathan (Jamie Flatters) is fleeing the city in the hope of finding his sister in Scotland. While the shy and withdrawn Sam (Keenan Munn-Francis) is Northward bound to see his Mum. A chance encounter puts the two together on the road, throwing them up against one obstacle after another until they open up about their respective anxieties.

It’s all fairly predictable stuff with easily identifiable character arcs. Nathan needs to straighten up and take responsibility while Sam needs to grow a backbone and stand up for himself. What makes it work is that both leads are giving thoroughly sympathetic and endearing performances in their respective roles. In the hands of a less restrained actor Nathan could be utterly insufferable but Flatters grounds him with a firm direction. His antics are played out with an infectious sense of fun and a touch of ignorance (not least in one uncomfortable scene where he grills a dark-skinned receptionist about where she’s ‘really’ from). However almost all his actions are focused on the constructive, relatable goal of reaching his sister.

Munn-Francis has the more challenging role as the good-natured, if frustratingly servile Sam. Clearly struggling with an emotionally empty home life and medicated to a shocking degree Sam is every bit the shrinking violet. Despite his position in the driving seat, it’s clear he’s living as a passenger, subject to life’s fickle whims. Unfortunately, this leaves him with much less interesting material to to work with. His wants and needs are shrouded in mystery for much of the films, leaving the actor little to work with besides anxiety porn.

Though it may be a touch insubstantial, Black Dog moves at a brisk pace, with pleasant company for the ride. Flatters and Munn-Francis have such charming chemistry that we’re happy to tag along as they drive, goof-off and argue with one another. So much so that when it comes time to confront the weighty emotional beats it feels earned. Their problems crash up against the film’s momentum in ways that feel honest, painful, and impactful. As the journey winds to an end, you feel for the two and hope the ride leaves them in a better place.