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401Panopticon 409The Devil You Know 417Karma” (Finch)
402Nautilus 410The Cold War” (Greer) 418Skip
403Wingman 411If-Then-Else” (The Machine) 419Search and Destroy
404Brotherhood 412Control-Alt-Delete 420Terra Incognita” (Reese)
405Prophets” (Finch) 413M.I.A. 421Asylum
406Pretenders 414Guilty 422YHWH
407Honor Among Thieves 415Q&A
408Point of Origin 416Blunt

4x21 - Asylum.png



Air dateApril 28, 2015

Running time43:48

Production code3J5421

Written byDenise Thé
Andy Callahan

Directed byFrederick E.O. Toye


ID(s) from IntroID.421/0428.15-A (Elias)
ID.421/0428.15-B (Dominic)

Images (35)


You are not interchangeable. I failed to save Sameen. I will not fail you now.

— The Machine

"Asylum" is the 21st episode of season 4, and the 89th produced hour of Person of Interest. It originally aired on April 28, 2015.


Reese and Fusco get caught in the war between the two newest POIs, rival crime bosses Elias and Dominic. Also, a tantalizing clue to Shaw’s whereabouts leads Finch and Root into a possible trap, and Control goes rogue to uncover the true intentions of the Samaritan program.

Origin of the Title

An asylum is a place of rest or refuge, either spiritual or political. It is also an out-dated name for a facility treating mental illness, such as the hospital where Samaritan had its base of operations.

Main Plot Points

The events in this episode are in Machine point of view and Samaritan point of view.

  • Persons of Interest: Carl Elias and Dominic Besson, whose battle for power has reached a crisis point.
  • Elias initiates a confrontation with Dominic by allowing himself to be taken hostage by The Brotherhood, along with Reese and Fusco.
  • Elias tricks Dominic into killing Link, in retaliation for Anthony's death.
  • Harper infiltrates the Brotherhood after receiving another text from Thornhill.
  • Control confirms Samaritan has infiltrated the government, and has turned her agents into its assets.
  • Root receives a call from Shaw that Harold believes is a trap.
  • Root and Harold follow the call to a mental hospital, where they are captured by Martine and Greer.
  • Root kills Martine by breaking her neck despite restraints, then surrenders.
  • The Machine agrees to reveal its location to save Harold and Root.

Episode Notes

Pneumatic tube system at Massachusetts General Hospital in Boston.

  • Elias' system of moving messages through the building in which he was found was via a system of pneumatic tubes. Networks of pneumatic tubes were used to convey documents and small objects around large buildings or over short distances, where there was a need to move urgent materials quickly. Objects are placed in canisters that travel at high speed through the tubes via compressed air or a partial vacuum. The systems are generally point-to-point, creating the need for complex networks of tubes. Frequently used in banks, post offices, hospitals, department stores and office buildings throughout the late 19th and early 20th century, electronic media has largely replaced these tubes for handling documents, although they are still used to move small objects, such as samples for analysis in hospitals.

Production Notes

  • The episode was originally titled "Black Site". A black site is a location where a highly secret governmental ("black") operation is taking place. The term generally refers to operations by the U.S. or U.K. military, the CIA or the British security services, but has come to refer to any location which serves as a governmental prison or other base of operations for a project that it not publicly acknowledged.

Bloopers and Continuity Errors



POI 0421 Shelly Surveillance Photo.png
  • The admitting physician at the hospital was played by John Preston. He is Carrie Preston's brother, and Michael Emerson's brother-in-law.[1]
  • On Control's surveillance picture of Shelly roaming the halls of the White House, Ross Garrison and Gabriel Hayward appear in the background.
  • Dominic refers to Harper as their mutual friend, a phrase often used by Finch.
  • When Harper mentions the Machine's alias, she refers to Thornhill as "her".
  • The key code Root uses to access the secure wing (222333) is the same one used in the movie "WarGames" when David is locked into the NORAD medical room.


  • "I go by many names, all derived from species of birds." (Harold, to the asylum physician)
  • "You are wrong, Harold. You are not interchangeable. I failed to save Sameen. I will not fail you now." (The Machine, to Harold)
  • "-Willing to exchange lives for location-" (Samaritan, to the Machine)
  • "Release them first, and you will know my location." (The Machine, to Samaritan)
  • "Do you ever lie awake a night thinking one day it may see you as a threat, or worse, irrelevant?" (Harold, to Greer, about Samaritan)
  • "Go home to your loved ones. Hold your daughter tight, because a new day is dawning. And those who impede progress, the disruptive, the aberrant, will be systematically purged from our society. There will be no mercy, no stay of execution. For some, this will be the end. But for others, a rebirth, a second chance to live the life they were designed for. Every life given a purpose. Samaritan will build a new world. A better world." (Shelly to Control)