Sarah Rubin Book order

Maths-whizz Alice has already solved a mystery or two. Persuaded by wannabe sidekick Sammy to investigate a scientist's disappearance, she's soon entangled in her trickiest case yet. Dr Learner is reputed to have invented an invisibility suit, but is whacky science really to blame for his vanishing? With the unlikely help of erstwhile nemesis Kevin, Alice solves the puzzle - only to face another. Should she reveal the truth, or protect her most devoted friend?

Looking at her ratty-tatty, used-to-be-white, too-big high-tops, and then at her skinny chicken legs poking up from the ground, you'd never think that Casey Quinn could ever be a ballerina. But just because Casey can't do ballet in high-tops doesn't mean she can't dance.