Professor Mercer is approached by his old friend CJ, a prominent investigative journalist who asks for help after she's poisoned with a rare and deadly nerve agent; with time running out, Mercer pieces together scant clues.

The Barnum Effect. After a passenger plane crashes into the Potomac River, suspicions focus on the pilot.

Zero Sum. Alec and the team take on a kidnapping case at the request of a desperate father.