In the study with the wrench / Peterfreund, Diana

"In the aftermath of Headmaster Boddy's murder, Blackbrook Academy has been thrown into complete disarray. Half of the student body hasn't bothered to return to campus--but those who have include Orchid, Vaughn, Scarlett, Peacock, Plum, and Mustard, now warily referred to by the other students as the Murder Crew. When another staff member is found dead and an anonymous threat begins to target the group, each of the teen's opportunistic reasons for sticking around come to light"--Provided by publisher.

After their headmaster is brutally murdered, the students of Blackbrook Academy are thrown into chaos, half of them not returning to campus. The ones who have--including Orchid McKee, Scarlett Mistry, Vaughn Green, Phineas Plum, Beth "Peacock" Picach, and Sam "Mustard" Maestor--have been titled the Murder Crew by the other students. Then, another staff member shows up dead, and everything comes to a boiling head at Tudor House.