“Call the guinea pigs, would you,” directs the brilliant psychiatrist Dr. Alex Gansa. The assorted subjects pile in to get their medication — all part of a week-long antidepressant drug trial taking place on the Oxford campus. The drug being tested is a form of ketamine — a horse tranquilizer and party circuit favorite. When trial subject Amy Katz is found dead, the drug-induced veil of contentment starts to tear.