The Sister's Grimm: The Unusual Suspects

This is the second book in Michael Buckley's series. In this one, we get to know the character Puck a bit more. Now that the girls finally have a foster family, they get to go to a school on a steady basis. Daphne is excited, because she gets to have Snow White for a teacher! However, Sabrina is much less excited, because school is school, and school in this town is horrible.
The teachers are super mean (except for Snow White, because she's awesome, but I think she's only a second grade teacher). The kids are mean and tired on top of it. When the girls stumble upon Sabrina's teacher's room (Mr. Grumpner) and finds that he has been killed, and wrapped in spiderwebs, they know something is going on.
There is another mystery brewing for the Grimms to solve. There are more deaths and this book is slightly gruesome as others are attacked and killed. They find out that the principle, monstrous students at the school, and Rumplestilskin have all been doing something horrible. Rumplestiltskin has been working with the Principle to use his instrument to hypnotize the kids into digging a giant tunnel under the force field and out of the town (it is protected by magic to prevent people from escaping).
Now the Principle's son has been affected, and he doesn't want to be a part of this anymore. Sabrina was hypnotized, but is broken out of it by the principle (the pied piper) and she runs off to save everyone. They are all spiderwebbed and stuck to the ceiling. They get caved into one of the sections of the tunnel.
Sabrina tries to free everyone, but Wendel, the principle's son, is almost killed. He is revived, but it was close. Sabrina was given magic matchsticks that can take her anywhere she wants to go. She only has about three, but they use one to get out of the cave, and leave Mr. Canis, who has turned into his wolf form, to fight Rumplestilskin. The monster kids are unconscious and they have been trained by Rumplestilskin to be murderous. They are returned to their original parents: Beauty and the Beast, The spider and Little Ms. Muffet, and the Princess and the Frog. They had been tricked by Rumplestilskin into giving up their children many years ago.
Everyone is worried about Mr. Canis when the tunnels cave in. He returns later on, but not until the next book. Sabrina thinks this is all her fault. She uses the last match to find her missing parents, who have been held captive by a mysterious group called the Red Hand. She finds that a young girl (Little Red Riding Hood) who is delirious has been keeping them there under a sleeping spell, and that she also has a dragon for a pet (the Jabberwocky) who sets the building on fire. The girl runs away with Sabrina's parents. Puck comes in to the closing portal to save Sabrina. The little girl still wants Mr. Canis for a dog, and Grandmother Relda for a grandmother. She will return!
The book ends with the house burning down around them.