The time has come for Atreyu Academy’s annual field trip, which is taking place at Mars Beach Resort Dome—a resort that mimics some of the most beautiful beaches on Earth. Alex is going there with Alice, Ariel, Jasmine, and Michelle as a chaperone.

What sounds like a simple task is made more complicated by Ariel and Michelle’s constant bickering devolving into violent fights. To make matters worse, the man who King Lucifer said would be coming to claim Ariel and Michelle has arrived at Mars with...