Eight years ago, Gavin, the artistic son of a Scots-Italian ice-cream dynasty, turned his back on Glasgow and moved south to London to make his name illustrating children's books. Now, frustrated and broke, his Uncle Sal appears with an offer. Gavin's father has sold the family business and to get his share of the proceeds, Gavin must return home for his father's birthday party. Swayed by the money, he sets off north and picks up a hitchhiker with a secret. Their journey is difficult but ultimately rewarding.