The newest POI’s curiosity could spell his doom when he finds himself embroiled in a dark government conspiracy – one that Finch is all too familiar with. Meanwhile, Reese uncovers something revealing about Finch’s past.

With Finch missing – kidnapped by his hacker nemesis, Root, Reese enlists Detectives Carter and Fusco to get his friend back, Meanwhile, The Machine never sleeps, disseminating a new number to Reese.

The Machine delivers the number of a cold case that leads Reese ever closer to catching up with Finch and his kidnapper, Root.

Carter tries to help Reese by engaging in mental warfare with the FBI; Reese has encounters with old and new enemies; Detective Fusco must protect supermodel Karolina Kurkova, the latest person of interest.

As Reese and Finch try to save a hotel maid's life, they encounter a litany of suspects; Detective Carter considers a significant offer from the FBI.

A lethal government operative who tracks and stops terrorist threats before they occur finds herself on the run – and the new focus of Reese and Finch's attention. However, their pursuit proves to be their most formidable when they discover that her remarkable skill set equals their own.

When a virus causes the machine to malfunction, numbers are issued irregularly; the team searches for an extremely elusive tech millionaire.

Finch and Reese team up with unexpected allies as they race to fix the machine; as Detective Carter tries to apprehend Cal Beecher's murderer, she finds herself up against HR -- a criminal organization.

The secrets of Finch’s operation before he enlisted Reese are revealed, including shocking ties to present-day events.