Gotham Academy second semester

"It's the second semester at Gotham Academy, and everything is back to normal. Of course, "normal" for Gotham's top prep school would be considered uncontrollable weirdness anywhere else! First, a bunch of students start walking out of their extracurricular activities with no explanation and signing up for a strange new society--Witch Club! Then, a stolen map of the Academy puts the students on a trail of ancient symbols and hidden chambers. There's plenty for the Detective Club to investigate--but Olive Silverlock is distracted by her new rebel roommate, Amy. Is Maps Mizoguchi right to be suspicious of a bad influence, or just jealous that she's losing her best friend? Plus, Detective Club is joined by the world's greatest detective--Batman!"--page 4 of cover