The movie opens with Holly Pierpoint, an accomplished professor in her 40s, heading to a conference
in Colorado Springs.
While en route to the hotel, her husband, Russell Pierpoint, calls to check if she has arrived.
During their conversation, Russell suggests planning a holiday together, but Holly seems
disinterested, citing exhaustion from the upcoming travel as a reason to stay home.
However, as Holly's car traverses the mountains, we discover that she is actually in Aspen,
indicating that she has lied to her husband.
The truth starts unravelling when the hotel receptionist addresses her as Mrs Alan.
A hotel employee named Dave, is tasked with showing Holly to her Black Diamond Suite,
which according to the management, is booked by her husband, Mr Alan.
It becomes evident that Holly is cheating on her husband, and is spending a weekend
getaway with her boyfriend, neglecting to consider the potentially severe consequences
of her actions.
Dave, who recently tied the knot, asks about her marriage and seeks advice for a happy union,
but Holly uncomfortably advises him to stand by his wife through thick and thin,
and to offer her flowers.
After Dave leaves, she discovers an envelope, instructing her to retrieve another envelope from the sink.
The envelope on the sink contains a message from her presumed boyfriend, urging her to
open a surprise in the closet, and suggesting wearing a blindfold for an extra adventurous experience.
Upon opening the box, Holly discovers a lingerie set and a pair of handcuffs.
Embracing the moment, she willingly engages in the excitement, donning the lingerie, and
blindfolding herself, while securing the handcuffs to the bed's headboard.
However, it seems like the next person entering the room is someone different, not her boyfriend.
Their encounter is intense, with Holly initially enjoying the passion, until it becomes too rough.
Despite her pleas for him to stop, the man continues, leaving Holly in tears afterwards.
After the man departs the room and enters the living area, it is revealed that he is
Holly's husband, Russell.
He has apprehended Everett Alan, Holly's 27-year-old boyfriend and her former student.
Russell sternly instructs him not to disclose anything to Holly; he must remain silent and
confined to the room, ensuring that Holly does not leave either.
Failure to comply with these instructions would result in severe consequences for Everett's wife,
Lydia, and his daughter Jessica, who are currently under Russell's control.
After placing a phone in Everett's pocket, Russell departs and leaves Everett alone with
Holly, who remains in shock from the mistreatment she endured.
Once Everett frees her from the handcuffs, she erupts in anger, directing her frustration
towards Everett, unaware that her own husband orchestrated the ordeal.
Despite Everett's repeated apologies, she is determined to leave.
Suddenly, Everett receives a call from Russell, warning him not to let Holly depart, or face
unforgettable consequences.
Apologizing profusely, he manages to persuade her to stay.
Everett desperately seeks forgiveness from Russell, but Russell, having discovered their
six-month affair through significant bank withdrawals, now demands that Everett continue
the vacation with Holly.
He clarifies that if Holly leaves or the police are called, he will kill Everett's wife Lydia,
whose muffled voice can be heard over the phone.
In a desperate attempt to cover up what Russell did to Holly, Everett begins giving excuses
to justify the situation.
While engaged in conversation, Holly receives a call from Russell, coinciding with a knock
at the door that distracts Everett.
Dealing with a security guard who lodged a noise complaint, Everett becomes occupied,
while Holly converses with Russell.
It is during this call that Holly discovers Russell is aware of her affair.
Instead of engaging in a confrontation, Russell enlightens Holly about the danger she has
unwittingly put herself in.
He describes Everett as a dangerous person with a history of affairs, that often end
with the mysterious disappearance of the women he dates.
Initially, Holly denies the accusations of infidelity, but upon realizing that Russell
knows everything, she decides to follow his instructions, which involve discreetly leaving
the hotel without Everett's knowledge.
After the call ends, Everett inquires about the conversation, and Holly claims it was
just a check-in from her husband.
To keep Holly confined to the suite, Everett slyly offers her a massage, taking away her
phone to prevent her from contacting anyone.
Restless and unable to enjoy the moment, Holly abruptly stands up, desperate to leave the suite.
Pretending that she needs to take a shower to wash the oils, she tries to take her phone
to the bathroom, but Everett grabs it first, forcing her to go empty-handed.
With no other options, Holly goes to the bedroom balcony, calling out for help, but no one
hears her screams.
Russel seems to be playing with them by telling his wife to run away, while ordering Everett
to keep Holly inside the hotel.
Meanwhile, a faint thud on the door captures Everett's attention.
As he breaks Russell's rule by leaving the room to investigate, Russell sends him a photo
of his wife with a knife held against her throat.
In a desperate plea for her life, Everett begs Russell, who instructs him to check the
bedroom balcony.
Everett breaks through the door, only to find
Holly innocently freshening up in the bathroom.
This is when Holly realizes that someone who would go to such lengths, breaking into her
room over a minor delay, is potentially far more dangerous than she thought.
Upon Everett's return to the living room, he receives a message from Holly's number,
indicating that Russell has taken possession of the phone.
Russell threatens to harm Lydia by removing one of her fingers for every action Holly
takes, and he has placed sleeping pills on the table, instructing Everett to drug Holly.
Desperate to uncover how Russell is monitoring him, Everett begins searching for hidden cameras,
while Holly retrieves her own sleeping medication intending to drug Everett.
Soon, Everett arranges a table on the balcony, offering the drugged drink, but Holly refuses,
insisting on white wine.
While Everett momentarily retrieves the requested liquor and puts sleeping pills in it, Holly
seizes the chance to add the sleeping pills to his glass as well.
However, when Everett steps outside and they are about to take a sip, a knock at the door
interrupts the moment again, prompting Everett to grab a knife and investigate.
To his relief, it turns out to be Dave delivering their food order.
After Dave departs with a tip from Holly, the couple begins to eat their dinner, which
appears to be a simple rare steak.
Throughout the meal, their conversation turns critical, with Everett and Holly blaming each
other for initiating their relationship, despite knowing they are married.
Their dialogue is abruptly halted by another knock at the door, accompanied by a message
on Everett's phone.
Russell informs him about Holly's tip to Dave, in which she has urged him to call 911.
Due to Everett's lack of caution, Russell has sent a gruesome warning.
He received his wife's ring finger from Russell.
While Everett is still in shock, Holly attempts to seduce him, but ends up holding a knife
to his throat, seeking to uncover his true intentions.
Thinking on his feet, Everett pretends to embrace her, showing Russell they are merely kissing.
Everett exposes her husband's involvement in the abduction of his family and the elaborate
scheme he designed as punishment.
Amid their conversation, Everett and Holly begin to feel the effects of the drugs, gradually
causing them to lose consciousness.
Upon regaining consciousness, Everett discovers himself lying on the bed, clutching a syringe,
while Holly remains handcuffed to a railing in the living room.
Accusing Everett of being a psycho serial killer, Holly warns him that Russell will
bring the police to put an end to his actions.
As Everett returns to the bedroom, he is startled to discover Russell gagged and bound to a chair.
Desperate to uncover the truth behind the torment and save his family, he attempts to
question Russell.
But with his tongue severed, Russell is unable to provide answers.
Everett then hands him a pen and paper, urging him to write down the name of the person responsible.
Later, he heads inside and frees Holly from the handcuffs, but she continues to hurl accusations
at him, further fueling his anger and frustration.
Holly is taken to the bedroom to see her husband, who is slowly dying while strapped to the wheelchair.
She breaks down in tears, questioning Everett as to why he would commit such an act, but
Everett's only response is that he is not responsible for her husband's demise.
Holly can't do anything but watch her husband's slow death, a result of the injection found
in Everett's hand.
She also discovers a note in Russell's hand, but chooses to keep its contents hidden from Everett.
Afterwards, Everett receives a call from the true mastermind behind the torment, the voice
distorted to conceal their identity.
This individual delivers an ultimatum that only one of the two lovers is permitted to
check out of the hotel to return to family life, while the other will face a terrible
end at the hands of his partner.
The choice is theirs.
The killer also reveals that Holly's daughter, Chelsea, is under constant surveillance, with
her roommate Sammy involved in the nefarious plan.
Holly is warned that disobedience could lead to harm befalling Chelsea at a single command.
As Everett contemplates his next move, Holly unfolds the note, only to find the word "Safe"
written on it.
Before she can fully grasp its meaning, Everett approaches her menacingly, wielding a knife
with the intention of ending her life to secure his return to his family.
However, their encounter is abruptly interrupted by the hotel management, diverting Everett's
attention momentarily.
Seizing the opportunity, Holly opens the safe concealed within the cupboard.
She recalls a brief conversation she had with her husband earlier, and tries the code associated
with their home's sprinkler system, which successfully unlocks the safe.
However, the safe reveals nothing but a storage card, leaving her puzzled about its significance.
As the hotel manager and security guard inquire about the whereabouts of their missing staff
member, Dave, Everett denies any knowledge of his disappearance.
However, the security team insists on speaking with Holly to investigate the matter further.
Understanding the need to work together for the sake of their families, Everett persuades
Holly to cooperate and talk to the officials.
After providing convincing answers to the manager's questions, Holly is finally left
alone with Everett again.
Suspicious of his involvement in the torment they have endured, she confronts him about
his possible role in the plan.
Everett explains that his wife's severed finger, sent earlier as punishment, was a consequence
of his failure to follow the rules set by Russell.
Even after seeing the finger, Holly remains sceptical, pointing out that Everett could
have killed Holly if the security guards had not arrived.
Justifying his actions, Everett reveals that he was driven by the need to provide for his family.
He also confesses that Russell was the one who mistreated Holly earlier in bed and set
up the rules, with the promise that if he adheres to them and stays in the room without
revealing anything, they would be allowed to leave in the morning.
As Everett tries to approach Holly to convince her,
a tragic accident occurs, causing the knife
to unintentionally stab him in the abdomen, resulting in severe and uncontrollable bleeding.
Despite the dire situation, Everett realizes that he cannot break the rules and call for
medical assistance, as his family is still in the clutches of the killer.
In his last moments, Everett implores Holly not to reveal their affair to his wife and daughter.
As Holly continues to offer words of comfort, Everett gradually succumbs to his wounds and
passes away.
Suddenly, Everett's phone rings, prompting Holly to answer it.
The mastermind behind this whole scheme congratulates her
for being one step away from her freedom.
To earn her release, she must destroy the phone in the microwave for thirty seconds.
Following that, she has two options: she can leave the hotel immediately, or if she wants
to find answers to the killer's motives, she can visit room 513 instead.
The killer assures her safety and promises she'll be free afterwards.
Following the instructions, she retrieves the room key from her dead husband's pocket.
After destroying the phone in the microwave, she chooses to visit room 513 to
uncover the truth.
Inside, she discovers the killer's surveillance monitors, capturing her every move.
While exploring, she stumbles upon a bound and blindfolded woman who turns out to be
Lydia, Everett's wife.
Holly assures Lydia of her safety, deferring questions about Everett's whereabouts.
Before contacting the authorities, her attention is drawn to the monitor, where she can check
the memory card she found in the safe.
As she opens the file of the CCTV footage, the shocking revelation comes as she sees
Russell setting up the cameras, with Lydia standing behind him.
The truth dawns on Holly, but it's too late as Lydia stands ominously behind her, ready
for confrontation.
Lydia, the mastermind behind the twisted plan, confesses to her creation and her collaboration
with Russell for revenge.
Lydia admits to being responsible for the disappearance of Everett's former girlfriends;
however, her breaking point was Everett's obsession with Holly, a reality she couldn't endure.
To make matters worse, Holly finds Dave's lifeless body, evidence of Lydia's destructive actions.
It becomes evident that Lydia killed Russell too, possibly because he disagreed with her
intention to eliminate Everett and Holly, while Russell, on the other hand, merely wanted
to torment Holly and catch her in the act.
They then witness the hotel management entering the diamond suite and discovering the gruesome murders.
It is at this moment that Lydia says that Holly's fingerprints are present all over
the suite, including on the syringe, the instrument used to sever Russell's tongue, and even the
knife used to kill Dave.
With the memory card as a last piece of evidence, Lydia maliciously breaks it, and flushes it
down the toilet.
Left with no means to prove her innocence, Holly gets out of control.
As the weight of her past mistakes and the destruction of her once-happy family consume
her, she bursts out in anger and hurls a vase at Lydia's head, abruptly ending her life.
The movie concludes with Holly pondering her own fate when two security guards forcefully
enter the room, demanding her surrender.