Claire McGowan’s engrossing psychological thriller “What You Did” explores the murky secrets and falsehoods that exist among friends. The narrative takes place at a college reunion, where Ali’s closest friend Karen accuses her husband Mike of something startling. As a result of having to decide between her spouse and her closest friend Ali’s background becomes revealed through a sequence of events. Ali is forced to revisit their shared university background as mayhem breaks out, revealing darker memories that someone would murder to keep hidden.