If-Then-Else

According to Nielsen Media Research, the episode was watched by 10.08 million viewers with a 1.7/5 ratings share in the 18 to 49 age demographic upon airing.

The episode periodically flashes back to 2003, where Finch is in a park playing chess with the Machine and using the games as analogies to various concepts he teaches it.

Several games later, as the Machine is appearing triumphant on many occasions, Finch tells it that he doesn't enjoy chess since it was created during a time of cynicism and societal imbalance.

The second option swaps the destinations of the two groups, which ends up with a wounded Reese detonating a grenade, killing himself and everyone in the security room, while Root professes her love to Shaw before dying.

In the last simulation shown, the whole group non-violently takes over the security room and stabilizes the market while Shaw talks the suicidal man out of bombing the train.

"If-Then-Else" was written by longtime Person of Interest writer Denise Thé and directed by Chris Fisher, also a veteran crew member.

[2] The episode's most notable development is the supposed death of the character of Shaw - the event sparked rampant discussion and response from the cast and crew.

Series executive producer Greg Plageman stated that the reason for Shaw's sacrifice was mainly due to actress Sarah Shahi's pregnancy with twins.

I get to pretend to be a superhero every week on TV, so that’s definitely the bitter part of the ‘bittersweet.’"[4] Plageman said that the main goal of the ending scene was to convey it "heroic" and a "self-sacrifice."

"If-Then-Else" aired on Tuesday, January 6, 2015 and, according to Nielsen Media Research, was watched by 9.97 million viewers with a 1.7/5 ratings share in the 18 to 49 age demographic.

Matt Fowler of IGN gave the episode a perfect rating of 10 out 10, indicating it is a "masterpiece" and praising the simulation format, the action scenes, the emotional value, and the ending.

[7] Shant Istamboulian of Entertainment Weekly lauded Emerson's performance in the flashbacks and felt the season marked the series' "creative peak."

He concluded with, "Moving like a rocket, this episode is fast, funny, exciting, and- ultimately - sad, ending with what seems like the loss of another team member.