A brilliant, touching and funny debut about an extraordinary friendship, a kidnapping, memory championships and a Russian bride

Saul Dawson-Smith can memorise the sequence of a shuffled deck of cards in under a minute; he can recite pi to a thousand decimal places and he remembers every conversation he's ever had. He is ten years old.

Howard McNamee is twenty-eight: lonely, overweight and poorly educated. He lives far from the scene of his difficult Glasgow childhood, in the home he shared with his mother. Struggling to pay his rent with a succession of menial jobs, Howard comes home each day and talks to the late Mrs McNamee, as he sits in front of the wardrobe that still contains her clothes.

These two solitary people find themselves forming an unlikely friendship, as Howard is taken under the wing of Saul's parents, thrust into a life in London (where he tries to navigate a bewildering new city and accidentally acquires a Russian internet fiancee), and Saul prepares himself for the World Memory Championships - the event he has been training for his whole life.

But as the pressure mounts on the young boy Howard realises he must act to save his small friend from a life of unbearable expectation. The decision he reaches turns all of their lives upside down.

Saul and Howard embark on an extraordinary adventure: the road trip they take together is an exhilarating escape-bid, a journey into Howard's past and a bewitchingly strange voyage of discovery for man and boy.