Kyle Miller (Nicolas Cage), a diamond broker, drives down a country road in his convertible Porsche trying to make a deal. He enters his sprawling, gated waterfront home, picks up a gold Zippo lighter by the pool and enters the kitchen. Sarah Miller (Nicole Kidman) and teen daughter Avery (Liana Liberato) are arguing about a party that night. The parents refuse to let her go to the party.
Kyle takes an envelope from a wall safe as he will be meeting a buyer later. Sarah brings a tray of food upstairs for the daughter, she's disappointed her plans for a nice family dinner have gone off.
Kyle goes to an area of the house under renovation with bare wood studs and plastic sheeting. Avery sneaks out of the house and jumps the estate fence, a girlfriend is waiting to pick her up. Kyle shows Sarah the lighter, she wants to get romantic but he has to go.
The doorbell rings and they see a police badge on the security video, the police are looking into neighbourhood burglaries. Kyle buzzes open the gate. Sarah notices Avery is missing as three men and a woman in masks invade the house. Sarah tries to drive off but is stopped at gunpoint.
At a large house party Avery joins in the fun. Meanwhile, the Millers are pushed to the floor, the intruders know the daughter is missing. The gang leader seems to know a lot about the Millers and demands the alarm system code. Sarah provides the number.
At the party a teen male shows Avery a safe full of cash and cocaine, he attempts to seduce her. Avery calls for a taxi and leaves.
The leader, Elias (Ben Mendelsohn) reveals the wall safe and demands Kyle open it. The other gang member Ty (Dash Mihok) says they have 10 minutes. Kyle stalls and refuses, the men threaten Sarah and say they know he has diamonds. Sarah huddles in fear. Kyle explains diamonds have micro laser codes so they can be easily traced as they all registered nationally. Kyle further explains the diamond business and tries to discourage the thieves. The younger thug, Jonah (Cam Gigandet) says he saw Kyle receive a lot of cash and the gang should just take the money and leave the diamonds. He eyes Sarah and she looks back. She recognizes him as a security firm tech who had done some work in their home recently.
Kyle stubbornly refuses to open the safe as the men threaten a panicky Sarah, Kyle tells them to let her go first. Upstairs Petal (Jordana Spiro) watches the Miller family home videos. She undresses and puts on purple dress.
Elias pulls out a loaded syringe loaded with sux, a medical paralysis drug. As he tries to escalate things Jonah pulls a gun on his partner and forces him to leave Sarah alone, he storms off to the kitchen angrily. In another flashback Sarah, an architect, gives Jonah a tall cool iced tea and they make small talk. On his way out Jonah stops by the pool, has a smoke and looks back at Sarah.
The taxi drops Avery off by the fence, she goes back in. Kyle has lost his glasses and is pain on the floor. Ty threatens to cut off his thumb to use on the biometric safe scanner.
In the kitchen Elias takes off his mask and tries to get close to Sarah, since she "already f*cked his younger brother". He tries to convince her to convince Kyle to open the safe. She pickpockets the syringe. Avery comes into the house, notices the intrusion and tries to escape but is caught. Kyle pleads for his daughter's safety, the Millers huddle together in Kyle's home office. Elias gives a sob story that he needs $180,000 or a new kidney for his mother. Sarah pulls out the syringe and puts Elias in an armlock, but Ty fires his shotgun, Sarah is able to convince them to let Avery go. In charge, Sarah now demands Kyle open the safe to end this thing. Kyle opens the safe, it is completely empty.
The thieves are shocked and crush Kyle's hand and demand the money. Kyle tearfully claims he put all the money into his house, mortgage and loans. He says he was fired and they are running out of money.
Outside Avery gets close enough to the fence to escape but is caught once again. Elias breaks open Kyle's briefcase and finds the diamond invoices. Kyle explains he doesn't take possession of the diamonds he is only a middleman using credit. Ty's phone rings, someone is calling to see how it is going. They still have an hour.
Elias whispers to Kyle they are under duress also. Elias tries to steady Petal down, she is upset and just wants to take what they can. They notice a portrait of Sarah wearing a dazzling necklace. Sarah shows them the necklace and asks them to leave as agreed. Bound and gagged on their knees, Kyle and Avery fumble for the zippo and try to burn the duct tape holding their wrists behinds their backs.
In the other room Sarah pleads with Jonah to let them go, she'll "do anything" he wants. Once again the intruders confront the Millers, Jonah telling Elias no one is to touch Sarah or Avery. A flashback shows Jonah get out of the Millers' pool and kiss Sarah. Kyle tells the men the necklace is a $99 cubic zirconium fake, he sold the real thing for the cash. Testing with the butt of a gun the flashy necklace shatters. Elias tells Kyle Sarah f*cked his brother, that's why they were there.
Upstairs Avery fights with Petal, in the distraction Sarah makes a break and Kyle throws a chair through the window, setting off the security system. Ty beats up Kyle as the security company phones to check in. Jonah answers calmly and buys some time. In the den Kyle is getting whupped but somehow manages to divert the syringe so Ty injects himself and drops to the floor. Kyle grabs the shotgun and staggers away. Elias recovers Sarah from the woods outside. Jonah needs the security code word and looks for Avery, she is hiding in the renovation room. Jonah sneaks up behind Kyle to recover the shotgun and Avery is forced to give the password to the suspicious security phone rep.
Elias shoots Kyle in the thigh then explains his problem. He tried to sell $180K in drugs but they were stolen, now the dealers want their money back and sent Ty along. Petal finds a screenshot print from the home security video, of Sarah and Jonah kissing, Kyle had it in his briefcase. Elias beats Kyle and Sarah, Jonah breaks it up and the two brothers fight.
Outside a security guard arrives and needs a signature on the alarm incident. The guard is adamant and Elias opens the gate. Sarah tries to explain to Kyle but he says it doesn't matter. At the front door Jonah shoots the guard in the head. Avery is frantic and says she knows where there is at least $200K. She will go with Petal back to the house party to get it. Jonah is doubtful but Elias agrees. As things quieten down in the house Jonah offers to take care of Sarah and Avery. A flashback from Sarah's point of view shows Jonah being overly friendly, she demanded he leave after the swimming pool kiss before anything else happened. Kyle tells Jonah to take Sarah and Avery to safety.
In the Porsche Avery drives, rounding a curve she deliberately crashes into a pole, releasing Petal's seatbelt at the last second.
In the house Ty rouses and stops Jonah and Sarah from leaving. In the car Avery is bloodied but Petal is unconscious. Ty beats up Jonah until Elias shoots him. Dying, Ty reveals that Jonah was behind the drug theft from Elias and gave it back already for $10K.
Elias is stunned. Left alone, Kyle and Sarah make their way to the reno room but Elias catches up and starts to choke Sarah. Jonah comes to her rescue and in the mess a plastic sheet rips revealing the large stash of cash hidden in the wall. Avery arrives with a gun and in the standoff Jonah shoots and kills his brother. Sarah comforts the badly wounded Kyle. He painfully says he was hiding the money for his family. As Jonah gathers the cash Kyle ignites a pool of solvent. The flames rush toward Jonah. Kyle gets up and nails Jonah's shoes to the floor and collapses. Jonah asks Sarah for help but grabs her and wants to die together. Kyle shoots Jonah who falls into the flames and dies. Sarah and Kyle make it out alive as the house goes up in flames. The Millers hug each other on the lawn.