Fifty people awaken in a darkened room, arranged in two concentric circles around a black dome. When they attempt to move from their designated platforms or touch the others, alarms sound off. When someone ignores the warning and leaves formation, a beam from the dome kills them, and their body is quickly removed. As the others panic, a man attempts to calm them, but the device kills him mid-sentence. Thereafter, every two minutes, another person is killed. After several people die, the group realizes that the room's technology allows them to use hand gestures to vote for who dies, while arrows on the floor show each person their own vote but not others'. They attempt to boycott the vote, but someone is randomly selected to die after two minutes.

Following someone's suggestion, the group buys time to think by deciding in advance to eliminate the elderly for the next selections. The captives discuss where they are, how they got there, who has abducted them, and why. A young man, Eric, remembers attempting to flee Los Angeles, and others concur. Eric says that he was pulled into the air, later waking in a red room with other humans. The old man next in line agrees, saying he saw and heard aliens. The disbelieving group eliminates him instead of listening.

After another member of the group aggressively targets a 52-year-old cancer survivor over the objections of people who do not consider her elderly, he is eliminated. Several people say they recognize the others: a man identifies the woman next to him as his wife, another man identifies the doctor he was having an affair with, and a tattooed man is eliminated after he admits to a cop's accusation of domestic violence. After several people are quickly eliminated, a black man claims the process has become racist. Several others dispute this, but when the cop goes on a racist rant, he is selected next.

The captives experiment with voting, find they cannot vote for themselves, and attempt to give one vote to every person in the circle. One man gives a second vote for a pregnant woman, so Eric votes for him; this causes a tie and the man is killed in a run-off vote. After several take their own lives by leaving formation to buy the others time, an atheist antagonizes the theists who praised the volunteers' faith. The atheist is briefly saved, but when he mocks the girl beside him for having her boss pay for her breast enlargement, he is killed. A homophobic lawyer targets a lesbian, and he is killed as a result. The group realizes that one of the final two people left must not vote (and be killed) to render a winner.

The group creates a schism. One bloc (led by Eric, a Marine, and the cancer survivor) believes that everyone should sacrifice themselves to save a pregnant woman and a little girl, while the other bloc (led by a bearded man and a rich man) wants to eliminate them immediately as a threat to their survival, as they believe everyone is equal and no special privileges should be afforded. The husband and wife team initially vote with the bearded man's bloc but the husband is forced to vote with Eric's bloc when they threaten to eliminate his wife. Under interrogation, the couple admit that they concocted the relationship to curry favor, resulting in the elimination of the "husband".

Eric's faction incurs heavy losses but eliminates the other faction, leaving only Eric, the pregnant woman, the girl, and a silent man who has never voted. Eric theorizes that aliens have used the process to learn about humanity's values. After the silent man is eliminated, Eric manipulates the girl to simultaneously sacrifice herself. As the girl dies, Eric instead votes to kill the pregnant woman, to the surprise of both, leaving him in a tie with the woman's unborn child. Eric votes to kill the child, becoming the lone survivor. He awakes in Los Angeles where he joins a group of people that are as varied as the contestants were in ages and ethnicities - including pregnant women - watching a fleet of alien craft float over the city.

The script was inspired by 12 Angry Men.^[1] Producer and star Nardelli, already a fan of the directors' webseries The Vault, became involved after they pitched the script to him. Pre-production took about three years.^[2] Nardelli said he was impressed with the script's ability to cover political, social, and psychological issues. In comparing it to Cube, he said Circle provides more answers and gives more of a definitive ending.^[3] Casting for some roles was broad, and others were specific; the intention was always to have a wide cross-section. The writer-directors did not intend for any character to be outright villainous, though several espouse intolerant opinions. Hann and Miscione wanted to address topical issues and provide a cynically tinged, antagonistic presence for the film.^[1] Principal photography began in February 2014^[4] and lasted two weeks.^[2] All of the scenes were storyboarded prior to shooting, and the directors tried to be as prepared as possible; regardless, they still encountered problems, as all actors had to be available for every shoot.^[1] Nardelli said that the psychological extremes experienced by the cast made it difficult to wind down after shooting.^[2]

After the film was released on Netflix, the writers and director opened a verified Q&A on Reddit. Among the many topics covered, the writers spoke about the artistic and logistical reasons behind shooting in one room, and the benefits of using unknown actors.^[5]

Circle premiered on May 28, 2015, at the Seattle International Film Festival.^[6] FilmBuff released it to video-on-demand on October 16.^[7]

On the review aggregator website Rotten Tomatoes, 57% of 7 critics' reviews are positive, with an average rating of 4.2/10.^[8]

John DeFore of The Hollywood Reporter called it a "Twilight Zone-y drama [that] works better than expected".^[9] Tony Kay of City Arts Online wrote: "The movie engineers suspense expertly, and there's puzzle-box fun in trying to piece together exactly what's going on as each prospective execution barrels forward".^[10] Ain't It Cool News wrote that although it is not "a fully realized concept", it is "thought-provoking" and provocative.^[11] Valeria Koulikova of the Queen Anne & Magnolia News wrote: "While the film's attempts to address social problems are beautifully done, leaving a bit of uncertainty in the end would have made a stronger finale".^[12]

• Circle at IMDb  
• Circle at Rotten Tomatoes