Control-Alt-Delete (Person of Interest)

"Control-Alt-Delete" is the 12th episode of the fourth season of the American television drama series Person of Interest. It is the 80th overall episode of the series and is written by Andy Callahan and directed by Stephen Surjik. It aired on CBS in the United States and on CTV in Canada on January 13, 2015.

The series revolves around a computer program for the federal government known as "The Machine" that is capable of collating all sources of information to predict terrorist acts and to identify people planning them. A team follows "irrelevant" crimes: lesser level of priority for the government. However, their security and safety is put in danger following the activation of a new program named Samaritan. In the episode, Control starts working on a new terrorist threat in Washington, D.C., but her discovery makes her question her loyalty when she realizes Samaritan may keep secrets from her. The title refers to "Control-Alt-Delete", computer keyboard command which generally interrupts or facilitates interrupting a function.

According to Nielsen Media Research, the episode was seen by an estimated 10.16 million household viewers and gained a 1.7 out of 5 ratings share among adults aged 18–49. The episode received highly positive reviews, with critics praising the writing, performances and momentum from the previous episodes.