What Happened to Monday (known in several territories as Seven Sisters) is a 2017 dystopian science-fiction action thriller film directed by Tommy Wirkola and written by Max Botkin and Kerry Williamson.^[8] The film stars Noomi Rapace, Glenn Close and Willem Dafoe.

What Happened to Monday was released theatrically in Europe and Asia, with Netflix distributing the film in the United States, United Kingdom, and Latin America on August 18, 2017.^[3][9] The film received mixed reviews from critics.

This article's plot summary may be too long or excessively detailed. (April 2022)

In the near future, overpopulation has resulted in a strict one-child policy, enforced by the Child Allocation Bureau. Any illegal children uncovered by the C.A.B. are taken and put into cryosleep indefinitely.

Terrence Settman's daughter dies while giving birth to identical septuplets. Unwilling to lose his granddaughters as well, he hides their existence from C.A.B. by pretending they're all one person. Each sister is named after a day of the week and can only leave the house on their respective day, during which they must live perfectly synchronous lives as "Karen Settman."

One night, Monday fails to return home after work. The next day, Tuesday retraces her steps and discovers Monday got the promotion they were up for and met their co-worker Jerry at a bar. Before she can investigate further, C.A.B. agents detain her.

At the C.A.B. facility, Tuesday meets presidential candidate and head of the bureau, Nicolette Cayman. Cayman says she knows about Tuesday's sisters, and sends C.A.B. agents to the Settmans' apartment to eliminate them.

The sisters manage to kill the agents, but Sunday is also killed in the process. Learning the agents used Tuesday's severed eyeball to bypass the building's retinal scan, the sisters suspect Jerry may have sold them out.

The next day, Wednesday leaves without disguising herself and confronts Jerry. He reveals that "Karen" got the promotion when she sent millions of euros to Cayman to fund her campaign. After a C.A.B. sniper kills Jerry, Wednesday flees his apartment.

The others remotely guide Wednesday to safety but are interrupted when a C.A.B. agent, Adrian Knowles, shows up at their apartment, concerned about "Karen." Surmising that Adrian has a relationship with one of them, Thursday convinces Saturday to leave with him. Saturday, a virgin, talks with Adrian at his apartment, finding out which sibling he was seeing.  She covertly links their bracelets while sleeping with him, allowing Friday to hack into the C.A.B. on a video feed; the sisters believe they have found Monday in a holding cell. Meanwhile, C.A.B. agents corner and kill Wednesday. After Adrian leaves his apartment, C.A.B. agents arrive and kill Saturday after she tells her siblings Monday was dating Adrian. The sisters' apartment is raided simultaneously by a C.A.B. squad led by Joe, the head of security of C.A.B. Admitting that she can not survive on her own, Friday sacrifices herself by blowing up their apartment to allow Thursday to escape and rescue Monday.

Adrian hears about the incident and rushes back to the Settman apartment. Thursday confronts him in his car, blaming him for her sisters' deaths. He claims he loves Monday and agrees to help rescue her. Adrian sneaks Thursday, concealed in a body bag, into C.A.B. headquarters. She secretly records a child undergoing cryosleep. Instead of being frozen, the child is incinerated. Adrian and Thursday discover Tuesday, missing an eye inside the cell. They search for Monday, only to discover that she has sold them out to Cayman.

At Cayman's campaign fundraiser, Thursday and Monday fight in a women's restroom, with Thursday accidentally shooting Monday. Meanwhile, Tuesday and Adrian broadcast Thursday's video footage of the incineration, leaving everyone at the event shocked. The now-traumatized crowd directs its attention on Cayman, who angrily confronts Thursday before her bodyguards pull her off. Monday comes out of the restroom brandishing a gun. Joe shoots Monday, thinking that she intends to kill Cayman, and Adrian kills Joe.

As the crowd flees, Monday reveals to Thursday that she is pregnant and asks her not to let the C.A.B. take her unborn twins. Thursday realizes Monday sacrificed her sisters in order to protect her children. Monday dies from her wounds. The Child Allocation Act is abolished, and Cayman faces the death penalty for her actions.

Thursday, Adrian, and Tuesday watch Monday's and Adrian's twins develop in an artificial womb. Now able to have their own identities, Tuesday decides to rename herself Terry, while Thursday chooses to continue being Karen.

• Noomi Rapace as the Settman siblings (Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday), septuplets sharing the identity of "Karen Settman".
• Willem Dafoe as Terrence Settman, the siblings' grandfather.
• Glenn Close as Nicolette Cayman, the head of the Child Allocation Bureau (C.A.B.).
• Marwan Kenzari as Adrian Knowles, a C.A.B. security guard and love interest of Monday Settman.
• Pål Sverre Hagen as Jerry, Karen's coworker.
• Tomiwa Edun as Eddie, the septuplets' doorman.
• Robert Wagner as Charles Benning

The film was originally written for a man, but director Tommy Wirkola had always wanted to work with Noomi Rapace. He pitched the idea of having a female as the protagonist to producer Raffaella De Laurentiis who agreed to the idea.^[6] Wirkola was inspired by films such as Children of Men and Blade Runner due to their realism and world building. The film was shot in Romania over 94 days with a budget of $20 million.^[6]

What Happened to Monday premiered at the 2017 Locarno Festival.^[10] The streaming rights for the film were purchased by Netflix.^[3]

Rotten Tomatoes, a review aggregator, reports that 59% of 37 surveyed critics gave the film a positive review, with an average rating of 5.8/10. Its critics' consensus says: "This high-concept sci-fi action thriller will make you stress-eat all the popcorn while Noomi Rapace (times seven) goes on a murderous spree to find out What Happened to Monday, but it may still leave you hungry in the end."^[11] According to Metacritic, which calculated a weighted average score of 47 out of 100 based on 12 critics, the film received "mixed or average reviews".^[12]

Jessica Kiang of Variety called it a "ludicrous, violent, amusingly dumb sci-fi actioner", remarking that although it is full of plot holes and Rapace's characters are thinly characterized, it is likely to become a cult film.^[5]

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