Just after his tenth birthday, the last thing Zak expects to hear is that his mum is having a baby and he has to give up his room for an ageing old grandmother who is coming to live with them! With the help of his friends and a series of cheeky pranks, Zak is convinced it''ll be no time before he can reclaim his rightful territory!But Zak soon discovers that his nani is no ordinary old grandma but a former chess prodigy, able to outwit and outdo him - and his friends - at every turn.Just as both players begin to forge a mutual respect and a friendship that might finally overcome all obstacles, Zak begins to notice things. Like how Nani sometimes forgets where she is... Or who Zak is... In a desperate bid to ensure his nani never forgets again, Zak enters her into the chess competition of a lifetime.But will Zak''s nani remember long enough to play?