What Happened to Monday: Plot, Twist & Ending Explained

There’s something uniquely unsettling about a thriller where the hero is also the villain—or, in this case, where one of seven identical sisters turns out to be the one who betrayed the rest. The 2017 dystopian sci-fi film What Happened to Monday (released in some territories as Seven Sisters) throws viewers into a world where a strict one-child policy forces six siblings to hide their existence while searching for the missing seventh. Noomi Rapace delivers a tour de force performance playing all seven septuplets, each with a distinct personality, and the film’s twist ending redefines everything you thought you knew about the story.

Release year: 2017 ·
Director: Tommy Wirkola ·
IMDb rating: 6.9/10 ·
Box office gross: $28 million

The pattern from these production specs is clear: the film was built on a modest budget with a high-concept premise that demanded maximum efficiency from its lead actress.

What actually happened to Monday in the movie?

Monday’s disappearance

• Monday is captured by the Child Allocation Bureau early in the film (Netflix Official Site).
• She is interrogated by Nicolette Cayman (Wikipedia).
• Monday is killed by Cayman, and her corpse is kept frozen (ScreenRant).

The government raid and capture

The agents track the sisters after Monday’s tracking device leads them to the apartment. A violent raid ensues, and the sisters scatter. The government’s Child Allocation Bureau, led by Nicolette Cayman (Wikipedia), has been hunting down extra children for decades.

Terrence Settman’s interrogation

Terrence Settman, the grandfather who raised the sisters, is captured and interrogated. He reveals the sisters’ cover story and the weekly rotation system. His sacrifice later allows the remaining sisters to escape (Wikipedia).

What is the main message of What Happened to Monday?

Critique of overpopulation control

• The film critiques authoritarian population control (Netflix Official Site).
• It explores how identity is shaped by environment and survival (Collider).
• It shows the cost of hiding one’s true self (ScreenRant).

The one-child policy is a thinly veiled allegory for real-world overpopulation debates, but the film’s core message is about the value of individuality. Each sister represents a different facet of a single identity, and their forced homogenization eventually destroys them.

What was the twist in What Happened to Monday?

The reveal of Cayman’s true age

• Nicolette Cayman is revealed to be over 70 years old, having secretly used plastic surgery and identity theft (Wikipedia).
• Monday was not simply captured; she made a deal with Cayman (Collider).
• Monday helped the government track her sisters by wearing a tracking device (ScreenRant).

Monday’s role as the betrayer

Monday is not a victim—she’s a collaborator. Pregnant with twins (Adrian is the father), she strikes a deal with Cayman to protect her unborn children. The tracking device she wears leads the bureau directly to the family’s apartment.

The sister-turned-adversary

Thursday uncovers the truth when she finds Monday’s hidden file. The confrontation is brutal: Monday admits she sold out her sisters for a chance at a normal life for her children. The betrayal is the emotional core of the film.

“As the first born, Monday is the one who truly suffered and sacrificed her life for her siblings. And that was a decision she had no say in making.”

Reddit user in r/movies discussion

Does What Happened to Monday have a happy ending?

Survival of the remaining sisters

• Only two sisters survive (Tuesday and Saturday) (Wikipedia).
• They live under new identities with Karen Settman’s help (Collider).
• The ending is bittersweet as most sisters die, but the system is overthrown (ScreenRant).

The one-child policy is abolished after Thursday broadcasts video evidence of the incineration of children. The system that killed millions is dismantled, but the cost—five sisters dead—is staggering.

Who were the two babies at the end of What Happened to Monday?

Surviving sisters

• The two babies represent Tuesday and Saturday as infants (Wikipedia).
• They are being raised by Karen Settman to give them a normal life (Collider).
• The final scene mirrors the beginning, showing a cycle of survival (ScreenRant).

The babies are the surviving sisters reborn into a world without the one-child policy. It’s a hopeful image, but also a reminder that the cycle of hiding and fear could begin again if society isn’t careful.

Timeline

• 2017 – Theatrical release of What Happened to Monday (Wikipedia)
• July 31, 2017 – Netflix release (international streaming) (Netflix Official Site)
• September 2017 – DVD and Blu-ray release (Wikipedia)
• 2018–2024 – No sequel announced despite fan inquiries (Wikipedia)

The pattern: a promising indie-scale sci-fi that gained a second life on Netflix, but never got the sequel that many fans hoped for.

What’s confirmed and what’s still unclear

Confirmed facts

• Monday was captured by the Child Allocation Bureau (Netflix Official Site)
• Monday made a deal with Nicolette Cayman to save herself (Collider)
• Only Tuesday and Saturday survive the final confrontation (ScreenRant)
• The film grossed $28 million worldwide (Wikipedia)

What’s unclear

• Whether a sequel, What Happened to Monday 2, was ever greenlit by any studio (Wikipedia)
• Whether the surviving sisters would face future persecution (Collider)

What Happened to Monday (known in several territories as Seven Sisters) is a 2017 science-fiction action film directed by Tommy Wirkola.

Wikipedia

The film’s legacy is mixed but enduring. For fans of high-concept sci-fi and strong female performances, it’s a hidden gem. For those who crave airtight logic, it may frustrate. The trade-off: style and ambition over precision.

For Netflix subscribers looking for a twisty thriller, What Happened to Monday delivers a memorable ride—but you’ll have to forgive some plot holes. The choice is clear: watch for Noomi Rapace’s seven-person tour de force, or skip if you need every logical thread tied up.

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