On this week's Person of Interest…

Fusco is investigated by internal affairs after a former cop put in prison begins to talk about Fusco's past as a dirty cop.

Internal affairs plans on digging up the body of Fusco's former friend, who they believe he killed.

Fusco reveals to Carter that he has killed people but he's on the path to being good.

At first Carter is upset, but after talking to John, she decides to help her partner out and remove the body with the help of Bear.

Meanwhile, John helps a poisoned doctor face his killer and get revenge.

Finch tells John that something is wrong with the machine after failing to save now three more people.

The machine has a signal problem and shuts off.