The Machine throws out the social security number of a guy called Michael Cahill, a man with no dependents who works as an air ambulance pilot. However, his helicopter is the regular delivery vehicle for a big-time smuggler called Neil Vargas, who is in the process of bringing in a big shipment of diamonds. Cahill joins Vargas, his hired hand Ajax and their precious cargo in their cover vehicle - an ambulance, which is being driven by an undercover Reese. Despite some attention from some pernickety cops, the delivery reaches its intended destination and the gang splits up.
Reese follows Cahill, where he appears to break into a house. Finch discovers that this is the home of a cop named Tully, but the affectionate welcome Cahill receives from the woman and child indoors suggests that Cahill is not a burglar. Finch learns that Tully has been deep undercover as Cahill for nine years trying to bring down Vargas and the big crime boss above him known as L.O.S.
What plan will Tully and Reese formulate? Will they get to take down L.O.S.? And who is his boss?
The duo investigate a young entrepreneur.
A troubled youngster, seeking revenge for the murder of his brother, hires Reese for a quarter.
When the Machine gives Reese and Finch the number of a down-and-out man, they are forced to turn to former Person of Interest Zoe Morgan for help.