The lost treasure by Cosentino and Jack Heath

The Mysterious World of Cosentino series book 3, Scholastic, 2018 ISBN 9781742994154
(Age: 7-9) Themes: Magicians, Adventure. Cosentino, the Grand Illusionist returns in another entertaining story, filled with magic, illusions, underwater adventure and daring escapes. Cos is the master of illusions. He's about to be "tied up, sealed in a glass ball and lowered into the ocean". Whilst the water pours in, he will have to undo his shackles, escape from his straitjacket, undo the padlocks, break out and swim to the surface.
Disaster strikes when the evil King of Diamonds activates his giant magnet to search the sea for his lost treasure. Cos is sent tumbling to the ocean floor trapped in his sealed glass ball. With the help of secret lock-picks he rips his straitjacket and prepares to swim to the surface. Meanwhile, Priscilla and Locki (the large padlock) who are Cos's best friends contend with killer whales and the King's giant magnet. Cos is given a magic underwater breathing device and is able to use his special magic to rescue his trapped friends.
This undersea adventure is filled with plenty of magic, help from new friend Captain Anchor, a chase by the King's submarine and frantic help from Locki and Priscilla. The lost treasure concludes with the secrets to the Magic Rope trick for budding magicians to try.
Black, white and turquoise cartoon illustrations add drama to this easy-to-read novel for ages 7-9.
Rhyllis Bignell