'Ghost School is stupid and rubbish, and, um, I'm not going to Ghost School ever again!'
Bumping is Humphrey Bump's best thing - even better than cakes and lollipops! But the nasty headmaster at ghost school doesn't agree. He expels Humphrey for - you've got it! - bumping.
So the other ghosties - Agatha, Tabitha and Wither - find Humphrey a place at still-alive school. They are also on hand to help him make friends. Wither invisibly writes a spooky poem on the board, Agatha sends children whirling into the clouds, and they all whisp out of Humphrey's satchel during lessons.
The still-alive children are so mean they only run away. But they are nothing compared to the still-alive headmaster who is the biggest bully ever. Can Humphrey gather all the ghosties together to fight the bully, save the school and make lots of new friends?