Peter Mullan stars as the titular tramp on a journey from Scotland to London in this British drama. Following years of living in shelters and motorway service stations, Hector McAdam (Mullan) hitch-hikes his way from Scotland to London to visit his brother Peter (Ewan Stewart) and hopefully reconnect with the rest of his estranged family. As he makes his annual pilgrimage to a London homeless shelter in time for Christmas, Hector finds himself confronted with figures from his past, more comfortable, life as the story of how he arrived in his current predicament begins to emerge.