Embedded codes are blue screens of code that can be seen from Machine Point of View (MPOV), disrupting the flow of data. Over the course of the second half of season two, the number and frequency of the code screen disruptions increased, suggesting degraded functioning of some type by the Machine.

The codes first appeared in the episode “One Percent”, following the upload of viral software into the internet by Kara Stanton. (“Dead Reckoning”) Over time, we learned that the virus was developed by Decima Technologies, whose representative, Greer, recruited Stanton. Once Stanton's mission was complete, Greer monitored the virus for the arrival of its zero day, when it would become active. As he did, Finch monitored the virus, having determined its target was the Machine, unable to do anything to stop it. At the time, it was unclear whether the blue screens were part of the virus's activity or the consequence of it.

The Codes by Episode

Below is a list of code screens by episodes in which they appear. Each screen directs the Machine to a particular piece of text, all available online.  For detailed information about the meaning of each code, visit the individual articles of codes by episode (also listed below).

One Percent

Main article: One Percent/Embedded codes

Code 01 Code 02 Code 03
Excerpt from Lady Macbeth's sleepwalking scene in Shakespeare's Macbeth Excerpt from the National Institutes of Health's bioterrorism page Excerpt from the National Institutes of Health's Anthrax page
  • Lady Macbeth's sleepwalking scene famously portrays her as a soul in torment, unable to rid herself of the guilt she feels at having pushed her husband to commit murder.

Booked Solid

Main article: Booked Solid/Embedded codes

Code 04 Code 05 Code 06
Excerpt from "Bin Ladin Determined To Strike in US" Excerpt from Revelation 16 About types of chemical warfare agents, likely from the webpage "Appendix B: Chemical Agents"
  • The Book of Revelation describes the end of the world. In Chapter 16, seven angels with bowls are announced, each bowl pouring forth a plague upon the earth.


Main article: Relevance/Embedded codes

Code 07 Code 08 Code 09 Code 10
Excerpt from Chapter 1 of "Heart of Darkness " by Joseph Conrad. Excerpt from "The principles of surgery" by John Bell and Sir Charles Bell. Excerpt from Voynich manuscript Excerpt from "The principles of surgery" by John Bell and Sir Charles Bell.
  • Conrad's "Heart of Darkness" is a novella about the collision between the so-called civilized and savage worlds at the height of the colonial period, and how a supposedly civilized man can become a savage. It was adapted as the 1977 Vietnam era film Apocalypse Now.
  • The Voynich Manuscript is an untranslated, putative 15th century Italian book believed to be a manual of plants and their medicinal qualities. The book has defied translation by experts, including WWII codebreakers, and some theorize it may be a fraud. Named for its 1912 purchaser, it is currently held in the rare book collection at Yale University.


Main article: Proteus/Embedded codes

Code 11 Code 12 Code 13 Code 14
Excerpt from Chapter 2 of "20,000 Leagues Under The Sea" by Jules Verne. Excerpt from "The CIA's Instructions For Breaking a Detainee's Will" Excerpt from "The Wasteland" by T.S.Eliot. Excerpt from "Project Trinity, 1945-1946" by Carl Maag and Steve Rohre

All In

Main article: All In/Embedded codes

Code 15 Code 16 Code 17
Excerpt from "Canto XXXII" of Dante's Inferno Excerpt from a CIA report on the materials and effects of terrorist-based chemical, biological, radiological, or nuclear attacks Excerpt from "Cinderella" as told by the Brothers Grimm
Code 18 Code 19 Code 20
Excerpt from "The Report of the Official Account of the Bombings in London on 7th July 2005" Excerpt from the Vietnam War My Lai Massacre Department of Defense Documents Excerpt from Book XVI. The Sixth Battle: The Acts and Death of Patroclus, part of Homer's Iliad
  • Dante's Inferno describes the journey through the nine circles of Hell. Canto XXXII describes part of the ninth circle, where traitors commit acts of treachery.
  • Cinderella is a well-known fairy tale with thematic elements including rising to attention after time in obscurity, and oppression of the disadvantaged by the advantage. Fairy tales are small morality tales designed to teach children life lessons, often by frightening them. The Grimm Brothers' fairy tales are known for including more graphic elements than other versions. In the excerpt, one of the step-sisters is being encouraged to cut off her toes to make the slipper fit. 

Trojan Horse

Main article: Trojan Horse/Embedded codes

Code 21 Code 22 Code 23 Code 24
Excerpt from "Balaam's Second Oracle" in the King James Bible. Excerpt from a translated letter from Dr. Wetzel to Hinrich Lohse, the Reich Commissar for the East in 1941, confirming command's decision to use gassing devices in the elimination of all Jews "who are not capable of work". Excerpt from "The Prince", a political treatise by Italian diplomat and theorist Niccolò Machiavelli. Excerpt from "A Retrospective on Counterinsurgency Operations", a CIA report on the Tay Ninh Provincial Reconnaissance Unit and its role in the Phoenix Program from 1969-70.
Code 25 Code 26 Code 27 Code 28
Excerpt from an Informational Memorandum on the subject of potential threats to Information Management Systems by cyber-terrorists. Excerpt from The Valley Of Fear, the final Sherlock Holmes novel by Sir Arthur Conan Doyle. Excerpt from the Introduction To Codes, Ciphers, & Codebreaking, an article by Greg Goebel on the concepts, terminology and origins of codebreaking. Excerpt from a version of the Bhagavad Gita, a 700-verse Sanskrit epic within the Mahabharata.

In Extremis

Main article: In Extremis/Embedded codes

Zero Day

Main article: Zero Day/Embedded codes

Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00001183200:00:11 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00004946700:00:49 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00015372400:02:33 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00015460700:02:34
Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00015548700:02:35 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00021490300:03:34 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00031084300:05:10 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00031997700:05:19
Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00032072000:05:20 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00032144100:05:21 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00033063600:05:30 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00033163800:05:31
Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00033293100:05:32 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00033428100:05:42 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00038415300:06:24 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00038795800:06:27
Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00090523900:15:05 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00113560500:18:55 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00121968100:20:19 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00122245800:20:22
Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00141353700:23:33 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00143432100:23:54 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00145254000:24:12 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00166891900:27:48
Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00167717500:27:51 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00176447500:29:24 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00194529900:32:25 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00233639000:38:56
Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00237862200:39:38 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00237920800:39:39 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00244899600:40:48 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00244922800:40:49
Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00251318300:41:53 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00251355200:41:53 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00251400100:41:54 Person.of.Interest.S02E21.720p.WEB-DL.2xRus.Eng.HDCLUB.mkv 00251432200:41:54

Origin and Purpose

Although the codes began appearing after Decima Technologies uploaded a virus, the virus itself originated on the Ordos laptop. The Decima virus was designed activate a routine in five months that would shut down the Machine (shown by red error screens), reboot and seeks its administrator by calling a specified public telephone. 184 seconds after shut-down, the Machine would reboot and call a designated phone number, allowing administrator access for 24 hours to whomever answered the public telephone the Machine called. It was Decima's plan to cover every public telephone on the streets of New York, thereby gaining administrator access for its own aims.

Unknown to Decima, the main virus also contained a second, hidden routine, designed by Finch to teach the Machine how to protect itself before the first virus activated. Each blue code screen was a lesson in threat or self-preservation. The images contained coded information about concealment techniques, codebreaking, counter-terrorism, the flaws of humanity (war, genocide, slavery), and the problems with reaching for godhood (the story of Babylon). It was Finch's intention that the Machine would learn how to protect itself when it was under threat, and to move itself to a new location. The five-month delay gave the machine time to slowly make the move to a new hidden location.

Harold Finch stated he designed this hidden program to free the machine of malicious human control. The full meaning and extent of this freedom is not yet known.  In the end, what appeared to be an attempt at sabotage by Finch turned out to be a fail-safe device designed to protect the Machine from outside interference.  


  • The producers rather carefully manipulated our perceptions of the screens by coloring them blue. In computer parlance a "blue screen of death" signifies a major computer failure, thus suggesting to us that the Machine was failing in some manner. Moreover, they used the red screens to suggest imminent danger, as they have with the red boxes.

Start a Discussion Discussions about List of Embedded Codes

  • Blue code in S2 gag reel?

    3 messages
    • I'm not sure what you mean by "blue screen". Is that the "official" name given to the images we see, generated by ...
    • Nope. The one I was thinking about was at the end of "Super" in season one. I just watched it again and that wasn't it. Now t...