This book was the sequel to the book Heist Society, also by Ally Carter, and in my opinion this one was not as entertaining.
Kat, a teenage thief, is up to her next big job, stealing the cursed cleopatra emerald. However, the job is harder than it seems as the person she is stealing from is a stellar con woman herself.
I don't know why, but reading this sequel was far less entertaining than the first. the characters seemed less vibrant and amusing, and the plot was pretty predictable.