The day after his tenth birthday, the last thing Zak expects - or wants - is to have to give up his room for an ageing old grandmother! With a face like an extra wrinkly raisin, hands as cold as an iceberg and always smelling of smoked fish and custard creams, there's nothing she gives Zak but the chills.

With the help of his friends and a series of tactics inspired by his school's chess club, 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 she is... Or how she keeps asking for people who are no longer by her side...

Once he learns the real reason she has been brought to live with them is because she is struggling with Dementia, Zak launches a desperate bid to ensure Nani never forgets who she is ever again. He enters her into the chess competition of a lifetime.

But will Zak's nani remember long enough to play?