A Games. A thief. A mechanical lioness. It's just another week in the Cosmic Realm!

The city of Cosmopolis is buzzing with excitement. The Cosmic Games are fast approaching, and eight champions are about to compete for a magical golden apple and a lifetime of glory. It's the event of a generation! But behind the scenes tensions within Olympus Inc. are running high as they struggle to hide signs of a rebellion, and the fact that a mysterious figure is trying to sabotage the Games. Who are they, and what do they want?

In Oxford, Peregrine is desperate to return to the Cosmic Realm but her mum is not keen. Surely, Peregrine's life is adventurous enough? The decision is taken out of Penelope's hands when Peregrine receives a letter from Athene herself, asking for Peregrine to compete in the Cosmic Games. How can Peregrine possibly compete against the other Academy-trained champions? Especially when someone is making it very clear that she should not be allowed to win . . .