Here is the description from the Amazon page for the book.
Colossus introduces the quick-witted and selfless Heather Stokes, and narrates the abduction and exploitation of Heather and three of her high-school classmates by the perverse yet enthralling Avery Rhodes. In fewer than 48 hours, the lives of Z, Witt, Monica, and Heather are shattered when they find themselves locked in closets and used as entertainment for Rhodes’s month-long “sabbatical.” The genius, the bully, the queen, and the martyr must navigate Rhodes’s appetites and temper in their own unique ways: submission, indulgence, subversion, and aggression.