This is book number 3 in the Amanda Lester series.
Purple rainbows, a mysterious crypt, and pots of gold . . .
Things are not going well for Amanda and the secret detective school. A priceless artifact has disappeared, a dangerous hacker is manipulating matter, and zombies are being seen all over the Lake District.
Then the real trouble starts. When her cousins go missing and her friend Clive is kidnapped, Amanda is forced to turn to someone she'd rather not deal with: her old boyfriend Scapulus Holmes. But then he vanishes too. Now's she's sure that arch-villain Blixus Moriarty is involved . . . or is he?