A mysterious coded message. A search for a fabled perpetual motion machine. A horse ride from hell. And a night in the exclusive Billionaire's Club House of Puzzles.

If Gerald thought his term in a Scottish Highlands school camp was going to be all snow-covered heather and tartan rugs he couldn't have been more wrong. With Professor McElderry in the clutches of Gerald's nemesis Sir Mason Green and a seemingly impossible task required to save his life, the stakes are high and the heat is on.

In The House of Puzzles, the fifth book of the Billionaire Series, Gerald, Ruby Sam and Felicity face their greatest challenge yet.

Richard Newsome lives in Brisbane with his family. He won the inaugural Text Prize for Young Adult and Children's Writing for The Billionaire's Curse, the first book in the acclaimed Billionaire series.

Praise for the Billionaire Series:

'What do you get when you mix Tintin, James Bond, and The Famous Five together? You get Richard Newsome's Billionaire series...The Crystal Code is Richard Newsome at his best!' Christchurch Kids Blog

'Filled with secret passageways and deadly booby traps, you'll be on the edge of your seat!' K-Zone

'Weird dreams, kidnapping, attacks by bandits, hectic chases and eerie explorations in archaeological sites...slapstick humour, verbal wit and a pervasive spirit of youthful exuberance.' Magpies

'A rollicking good yarn.' Weekend Herald

'I loved this book. I really did. Ever since I got the first book in this series, I was on the lookout for more! The characters - Gerald getting tangled up in relationships - and the plots were just fantastic.' YAAR-A reviews Corinna, age 13, Canberra, Australia

'An irresistibly fun-tastic tale that's virtually guaranteed to keep youngsters reading, chuckling and desperately waiting for the next book in the series.' Independent Weekly

'It has humour that is just off centre enough to appeal to children as well as a few pearls of wisdom thrown into the mix. Fans of the series will lap it up and those who haven't read the earlier books will no doubt want to go back and read the rest. Good fun that could equally be enjoyed by anyone young at heart.' OrangeDale blog

'Plenty of plot twists to keep readers guessing and eager for Gerald's next adventure.' Magpies