A drug bust went very, very wrong
The DEA caught a group with a duffel bag full of NZT but, somehow, a few pills went unaccounted for. That night, Casey and members of his DEA team took the “missing” NZT. When one member of the team killed another and the rest couldn't find a way to cover up the crime, Casey went into panic mode and held Finch hostage—a tactic that got him killed.