You Have to Stop This: The Secret Series, Book 5

You Have to Stop This: The Secret Series, Book 5 by Pseudonymous Bosch

In this Secret book, they finally find the secret, but... it is a joke. The school gets to visit a mummy exhibit. However, they accidentally break off a finger. Later the mummy disappears, and they are accused of stealing it - but they discover it walked away. They stow away in boxes and hope to be shipped away to the mummy. They wake up and think they are in Egypt, but discover they are in the recreation in Las Vegas. There, the leader of bad guys, Lord Pharaoh is putting on a magic show. He tries to get a key artifact from them. However, they are able to foil him and get everything back in order. And at the end, Max-Earnest gives a middle school graduation speech. This nicely wraps up the secret series in zaniness.