Magnus Chase and the Ship of the Dead (Book 3)

Winner of the Goodreads Choice Award 2017 for Best Middle Grade & Children's!
Loki the trickster god is free from his chains. Now he's readying Naglfar, the Ship of the Dead, armed with a host of giants and zombies, to sail against the Norse gods and begin the final battle of Ragnarok.
It's up to Magnus Chase and his friends to stop Loki's plans. Along the way, they will face angry sea gods, hostile giants, and an evil fire-breathing dragon. But Magnus's biggest challenge will be facing his own inner demons...