There aren't many stand-alone mystery books in YA, are there?
Well, if Diana Renn's Tokyo Heist is any indicator, more mysteries are needed. Immediately. Or maybe just more of her mysteries.
It is annoying to no end when a mystery book's mystery doesn't make sense. (Cough... PLL... cough... HACK...
Such guilty goodness...) You know what I'm say'in/ insinuat'in:
Why would Ali's killer be someone that the readers already know? Why give clues to whom the killer actually is? That's too boring. Wait. I know! Let's throw in a random evil twin sister halfway in without notice and see where the tide takes us! Yay!