Rating: WARTY!
I reviewed the first of these positively, and I really liked it, but this one fell far short of the glory of its predecessor, I'm afraid to say.
The stakes are a lot lower, too. In the original, Frankie's cousin Kat had disappeared, so it was imperative he find her. In this one, maybe the teacher was poisoned, maybe not. Maybe he was the intended victim, maybe not. Frankie doesn't seem very interested in finding out the real details. Instead he prefers to go haring off on improbable wild goose chases.
There was a lot more whimsy and crazy in the first one, which for me added to its appeal. All of that seems to have vanished from this one, and Frankie seems far less capable here than he did previously. He doesn't even secure the pie as evidence, which is sad.
On top of that, he's not a very likable person here, especially since there's a small thread of misogyny going on, which is some ways is understandable given that we have a juvenile boy as the main character, but this is written by a woman, and I had to wonder why she made him so antagonistic towards girls. He barely tolerates his own cousin who he actually likes. I didn't appreciate that and I think it's a foolish way to write a character. it's never to early to teach respect for women (and men!) and it's always too early to teach the opposite as though it's acceptable.
Frankie's new teacher is supposedly poisoned by a lemon pie, and Frankie takes it upon himself to try to figure out who was behind it. He jumps on everyone, starting with the teacher who bought the pie, and when he learns she was not at fault, he tries to trace the pie back to see who might have had access to it, and who also wanted to bring harm to someone. Despite Frankie's rather aggressive and accusatory demeanor, everyone unaccountably gives him the time of day and evidently tells him the truth, so there really isn't a lot he has to do, nor are there any red herrings or real mysteries other than the main one - even assuming it is a mystery. I didn't finish the book so I don't know.
Maybe middle-graders - the intended age range - will get sufficient out of this to make it a worthy read, but I don't see my two boys being interested in this story at all, and I certainly can't recommend it. I couldn't even bring myself to finish it because it simply was downright boring.