It is Betti’s birthday, today is meant to be all about her. When she comes downstairs to check on the party preparations, her excitement quickly fades as Mam pulls a burnt cake from the oven. With no cake to serve, they set off into town to find a replacement. What should be a simple journey soon becomes far more complicated with the arrival of an unexpected gatecrasher: the Bwgan. It’s small, slow, annoying, and worst of all, it constantly demands Mam’s attention. Betti tries to take control of the situation, but the harder she resists, the more things spiral.