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← Season 4 Person of InterestSeason 5 (Flashbacks in parentheses)  
501B.S.O.D.” (Finch) 506A More Perfect Union 511Synecdoche
502SNAFU” (The Machine) 507QSO 512.exe” (Multiple simulations)
503Truth Be Told” (Reese) 508Reassortment 513return 0” (The Machine)
5046,741 509Sotto Voce  
505ShotSeeker 510The Day the World Went Away
return 0

POI 513 Episode Image.png



Air dateJune 21, 2016

Running time43:38

Production code3J6013

Written byJonathan Nolan
Denise Thé

Directed byChris Fisher

Viewers6.51M (18-49: 1.0 rating)

Images (36)

Everyone dies alone. But if you mean something to someone…

if you help someone or love someone, and even a single person remembers you… then maybe you never really die at all?

— RIP, Person of Interest

[Suggest quote]

Series Finale. Return 0 is the 13th episode of Season 5, and the 103rd produced hour of Person of Interest. It originally aired on June 21, 2016. It is the final episode of Person of Interest.


Finch, Reese, Fusco and Shaw embark on one last mission to prevent Samaritan from destroying the Machine and cementing its hold over mankind.

Origin of the Title

In many programming languages, particularly C-style languages (e.g., C, C++, Rust), the main function may return a single number, to indicate the success or failure of the execution of the program. 0 indicated a successful run, anything else corresponded to some error condition.. In this episode, both Samaritan and the Machine are shut down. The term also metaphorically refers to a happy ending, such as Finch's.

Main Plot Points

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

  • Person of Interest: None
  • The upload of the ICE-9 virus has devastating global side effects.
  • Finch and Reese attempt to destroy a Samaritan copy located in the vault of the Federal Reserve Bank, but it uploads itself to an orbiting satellite as a last resort.
  • Shaw and Fusco defend the Machine, learning of Blackwell's role in Root's murder. Shaw is shot, and Fusco is severely wounded in the process.
  • Finch attempts to sacrifice himself to upload a copy of the Machine to destroy Samaritan, but is preempted by Reese who sacrifices himself to save Finch instead.
POI 0513 Russian Satellite.png
  • The Machine follows Samaritan to the satellite and destroys it once and for all.
  • A week later, ICE-9 is contained and the "Northern Lights" program rendered defunct. Sen. Garrison is held accountable for his actions.
  • Shaw tracks Blackwell down and executes him for Root's murder. She then meets with a recovering Fusco and takes Bear with her as she leaves.
  • Finch returns to his fiancée, Grace, in Italy.
  • Having won, the Machine downloads into Finch's computer system and contacts Shaw.
  • The events of the very last scenes are from the perspective of the Machine's duplicate, born out of the destruction of Samaritan and the successful uploading of the Machine's core code to an orbiting satellite.


Episode Notes

Nolan on how The Machine beat Samaritan: "I think a part of it was all that relentless training, in a sense. Finch and Root trying to scheme out how this would work but also running these simulations with the Machine in order to figure out how it could win in its most pared down form. So you've got this decommissioned Soviet satellite and these things were up in there in their most compact fighting form. Sort of like how armies used to march out and select one champion to represent them, and the fight would be decided with that champion and the rest of the army would abide by that outcome. But at this point, the armies have been decimated and destroyed and only the champions remain. The sparest algorithmic versions of these ASIs uploaded into the satellite like two strands of DNA having a kung fu battle. So kind of fun, but also kind of hard to visualize. Both of them have been reduced to their respective essence, and in that form, the Machine was going to kick Samaritan's ass."[1]

Production Notes

Gizmodo wrote: "Person of Interest was one of the smartest shows on television, turning a fairly pedestrian format into a kind of modern cyberpunk. It asked nuanced questions and tried to give nuanced answers (that’s how Root went from being an antagonist to an ally. She wasn’t always right, but Finch wasn’t always right, either). And that was what the show did: find the line in the murky world of surveillance technology and artificial intelligence." [2]

Person of Interest won the People's Choice Awards in 2012 and 2016.[3]

Bloopers and Continuity Errors


  • "Bunsen Burner" - Cuts (when Finch gets to the rooftop)
  • "Metamorphosis 1" - Philip Glass (when Reese uploads The Machine's copy to the satellite)


  • In the final scene of the series, Shaw answers the pay phone on the southwest corner of 49th St. and 6th Ave. and looks up at the camera. This scene takes place on the same corner where Reese looked at the camera in the “Pilot”. He also answered the same pay phone in “Firewall”.
  • The machine uses a tape recording (on a Nagra 3) to inform its duplicate of its mission. Finch also used a tape recording (on a similar Nagra E) to, in a way, inform Reese of his mission in "Pilot".
  • The final sequence of the show was originally meant to have the song "Heroes" by David Bowie playing over it. However, Jonah Nolan changed his mind after hearing Ramin Djawadi's score.
  • When Reese asks what Fusco did with Agent LeRoux, Fusco tells him he put the man in a trunk. In the pilot, Reese tells Fusco that Stills is in his trunk and uses it to blackmail Fusco into helping him. He also tells Finch they'll need his trunk after Fusco killed Artie Lynch. (“Matsya Nyaya”)
  • The date of Destruction of Samaritan is uncertain. In the end of the episode, a gravestone (presumably Reese's) reads November 13, but in the Machine's flashbacks, it was Tuesday. The criteria are contradictory, as the year can't be in 2015 or 2016, which was implied in previous episodes.
  • Assuming the aforementioned gravestone is Reese's, its displayed surname is unique, though only the letters TAL are shown before the camera cuts away. This may be a clue to Reese's original surname (perhaps Talbot, although this does not contain an 's' as established in Many Happy Returns).
  • The buildings where Finch and Reese are during The Machine upload to the satellite are 1155 and 1133 6th Ave, respectively.[4]
  • In the scene where Samaritan hacks into the billboards at Times Square, writers Jonathan Nolan & Denise Thé appear in the background, being part of the crowd surrounding Finch, gazing at the screens.



  • "Detective Fusco, meet the Machine" (Finch, to Fusco)
  • "When I hired you, I suspected you were going to be a great employee. What I couldn't have anticipated was that you would become such a good friend." (Finch, to Reese)
  • "The suspense is killing me... in addition to the gunshot wound." (Finch, to the Machine)
  • "In addition to this being now, it's also probably the end." (Finch, to the Machine)
  • "That's so perfect. You learned the secret of life and you've forgotten it." (Finch, to the Machine)
  • "I helped bring you into this world, Now I'm going to help usher you out" (Finch, to Samaritan)
  • "I know I've made some mistakes. Many mistakes. But we helped some people... didn't we?" (The Machine, to Finch) "Yes. Yes we did." (Finch, to the Machine)
  • "Goodbye" (Finch, to the Machine. His last words of the series)

The Machine

  • "I was built to predict people, but to predict them you have to truly understand them. So I began by breaking their lives down into moments... Trying to find the connections, the things that explained why they did what they did. And what I found was, the moment that often mattered the most, the moment when you truly found out who they were... Was often their last one." (The Machine, to her duplicate)
  • "Goodbye, Harold" (The Machine, to Finch)
  • "I chose you for exactly who you are, but there's something I think Root had wanted to say to you. You always thought there was something wrong with you because you don't feel things the way other people do. But she always felt that was what made you beautiful. She wanted you to know that if you were a shape, you were a straight line. An arrow." (The Machine, to Shaw)
  • "If you can hear this, you're alone. The only thing left of me is the sound of my voice. I don't know if any of us made it. Did we win? Did we lose? I don't know. But either way, it's over. So let me tell you who we were. Let me tell you who you are. Someone once asked me if I had learned anything from it all. So let me tell you what I learned." (The Machine, to her duplicate)
  • "Everyone dies alone. But if you meant something to someone, if you helped someone, or loved someone, if even a single person remembers you, then maybe you never really die. And maybe, this isn't the end at all." (The Machine, to her duplicate. Her last words, and the final words of the series)


  • "Oh, I like this new side of you, Finch. It's terrifying, but I like it!" (Reese to Finch)
  • "When you came to me, you gave me a job. A purpose. At first... well, I've been trying to save the world for so long; saving one life at a time seemed a bit anticlimactic. But then I realized: Sometimes, one life, ...if it's the right life, it's enough. Goodbye, Harold." (Reese, to Finch. His last words of the series)


  • "I figured I should say goodbye. Sorry, Root. This... just isn't my thing." (Shaw, at Root's grave)
  • "God, you have her bad timing too." (Shaw, to the Machine, referring to Root)
  • "If we were eating donuts and shooting cardboard cut-outs, you would be in charge." (Shaw, to Fusco)
  • "Is this the guy who killed you? ...Killed her, I mean." (Shaw, to the Machine, talking about Blackwell)
  • "Goodbye." (Shaw, to the Machine)
  • "A few years ago I would have just killed you without a second thought. But then I met some people; some good people. And they taught me the value of life." (Shaw, to Blackwell) "Those people, they wouldn't want you to kill me." (Blackwell) "You're right. But they're all dead." (Shaw)
  • "I'm alive." (Shaw, to Fusco)
  • "I'll see you when I see you" (Shaw, to Fusco. Her last words of the series)


  • "I knew you guys were crazy, but this is next-level nuts." (Fusco)
  • "Try not to die" (Reese, to Fusco), "Yeah, I love you too" (Fusco, to Reese)
  • "Not if I see you first" (Fusco, to Shaw. His last words of the series)