The Staff of Serapis

Rick Riordan's The Staff of Serapis is a crossover adventure for 10 year olds that puts Annabeth Chase and Sadie Kane on the same New York subway train.

What happens

Annabeth is having a rotten day. She's messed up an interview, missed a film with Percy, and trodden in cow muck in Washington Square Park (Hera's idea of a joke, she's sure of it).

Then she spots a monster on the platform. It's a wolf and a lion stuck together in what looks like a giant hermit crab shell. And it ignores her completely. Monsters never do that, so of course she follows it.

A few stops later, a blonde girl in combat boots with purple streaks in her hair is whacking a dog-shaped monster with a glowing staff. That's Sadie. She's a magician who uses Egyptian magic, and she has never heard of a demigod in her life.

Watching the two of them work each other out is half the fun. Annabeth likes to read up on a monster before she fights it. Sadie's plan is to think on her feet and blast things into "teeny-tiny bits". Sadie is very British and very funny (there's a camel, and it's brilliant, and that's all I'm saying). Annabeth, who's usually the most experienced person in any fight, suddenly feels like a beginner again.

There's a nice big question underneath the jokes too. If the Greek gods are still around, why not the Egyptian ones?

The monster is hunting for its missing piece and for its master. The god they end up facing wears Hawaiian swimming shorts and a flowerpot on his head. It's silly and exciting at exactly the same time, which is what Riordan fans come for.

This one works best if your reader already knows both worlds. It's packed with little references to past quests, and it assumes you know who Percy and Carter are. A reader who's new to both might feel a bit lost.

The fights are fast and loud, and a subway train comes off its tracks (the passengers have already run for it). Sadie also mentions that her mum died, as part of her own history. None of it is more than Percy Jackson fans are used to.

What to read next

Annabeth only knows about all this because Percy met a magician first, near Moriches Bay, fighting a giant crocodile. If they want that half of the story, The Son of Sobek is where Carter Kane goes after a swamp monster on Long Island and runs into a boy with a glowing sword.