This was... fine? It went quickly so I wasn't bothered. The story is fine. The writing is fine. The plot is boilerplate murder mystery, you could tell what was coming well before it came. It's meant for younger readers, clearly, so that didn't bother me so much. What kept me from loving it was the characters themselves and some choices the author made. The biggest of which is hinging some major plot stuff on a WILDLY inaccurate description of how Facebook even works. I feel like if you're going to describe young people and their social media you ought to familiarize yourself with how it works. Young people always know the ins and outs of the social media platforms they're using. Miranda clunkily fumbling through facebook like someone's elderly parent was just badly done.
The biggest issue for me though is that every Allerdon not named Miranda was flat and portrayed as anywhere between naive and actually stupid. Lander is described repeatedly as the perfect kid who can do no wrong and is so smart and then is actually depicted as a lovesick dingdong who switches her brain entirely off if a boy she thinks is cute walks by - enough to not speak up when she is literally dragged to jail and charged with murder? Really? And the Allerdon parents... just yikes. I get that part of this story is giving all these privileged cushy people a massive wake-up call, but goodness.