House Arrest is the second book in the Murder House Trilogy and the 23rd book in The Hardy Boys Undercover Brothers series. It was published on July 8th, 2008 by Aladdin Paperbacks, an imprint of Simon & Schuster in paperback and as an ebook. 
- See also Deprivation House#Plot summary
After learning that while Mitch was the murderer, but wasn't the one sending threats to Deprivation House contestants, Frank and Joe Hardy continue their investigation for American Teens Against Crime, on the reality TV show.
Some of the contestants think the producers might be behind the threats, others disagree. Meanwhile, more luxuries have been taken away, including hot food, freezer, and heating. Hal suggests that the company may be trying to spice up the show, and make it seem like the house is haunted, this disturbs Brynn and she panics ruining to her room, Frank follows and tries to comfort her. While with her he can see why Joe likes her so much.
Downstairs Bobby T shows Joe pictures of the scene of murder that happened in the house years ago. As it turns out a TV move about the murder, untitled Witness to Evil, will be reran later this week.
Later that night James Sittenfeld life is threatened when he almost eats broken glass that has been frozen into the ice cubs in the water jug. His month is cut badly but he only goes for medical help after thinking up a fake story, fearing that if the truth was known the show would be shut down. The Hardys add Mikey Chan to their suspect list, since he has known knowledge of James' habit of chewing ice.
The contestants are up early the next morning for the next competition, the goal of which turns out to be: get as many potato chips in to your trunk as you can before the time runs out, who ever has the most wins. If you are caught so much as licking the salt of your fingers during the contest, you will go with nothing to eat but bread and water for two days and will have to make meals for the rest of the contestants. Frank wins the Junk in the Trunk contest but not before Ripley Lansing is caught eating a chip...
Brynn starts hanging out with Frank, and he wonders if it could have any thing to do with the fact that he will be choosing the next deprivation. She tells him this is not the case, saying that with all the strange goings on in the mansion, and having noticed the way Frank handles emergencies, feels safer around him. Frank feels that Joe could be getting a little jealous.
Frank and Joe haven't seen Mickey in some time, who they still suspect could be up to something, set out to look for him. When they find him, he is in an outrage, saying that Ripley is cheating and eating cooked food. Both the Hardys aren't really concerned about it but still think it might be worth looking into.
So Joe goes to talk with Ripley, as it turns out, like the brothers, she to suspects Mickey is up to no good. While Joe is still with Ripley, Veronica Wilmont takes her to another Deprivation Chamber so Ripley can talk about her punishment. When they don't come back for half an hour, Joe becomes suspicious. Could Ripley Lansing be in cahoots with the producers?
Later Frank finds Brynn shortly after she has been cut by knifes someone planted in her bag, yet another strange event on Deprivation House, when Mary Moore clams she saw a little girl outside by the woodpile and was then knocked to the ground from behind.
Brynn says she doesn't feel safe anymore and is thinking of dropping out, Frank asks her to stay, saying that if she does he will let her pick tomorrow's deprivation.
The next morning when Frank announces the next deprivation is TV, the house is in an uproar, as most of the teens were looking forward to the Witness to Evil TV movie. Out of all the contestants, Mikey is the most upset, though.
Later that day Ripley tells the brothers that Mary told her Veronica ordered more wood to be cut, Frank offers to do it and heads out for the woodpile. Before he can get to work, Frank hears someone laughing, the woodpile starts to rumble, and then falls on top of him. Frank is lucky and is not badly hurt, and the production crew assure every one, the whole thing was just an accident, the Hardys are not convinced however, and even more skeptical when it turns out that the camera filming the woodpile was blocked.
The Hardys decide to talk to Mary, since she told Ripley to tall someone to get wood, but according to her, she did no such thing. Joe notes that he needs to keep his eye on Ripley
After dinner Joe fins Bobby T staring at his laptop in disbelief, someone posted a comment on his blog that reads, "Nice blog, Bobby, maybe your friends and family can read from it at your funeral." Frank quickly checks his e-mail and sure enough he has received a similar threat, "You and your brother may have lived most of your life, apart, but if you stay in this house you'll die together." (the Hardys are undercover as two brothers separated at birth) Frank investigates and finds out every one in the house has been threatened, or so they claim.
The next morning, another competition takes place, the Prissy Primers Challenge, for this contest the swimming pool has been filled with every grooming product you can think of. Shampoo. Toothpaste. Hair gel. Pimple cream. Cologne. Makeup. The contestants are divided randomly into teams of four, which ever team has the most grooming product when time runs out, wins.
The competition is going well, when Frank makes a disturbing discovery – the dead body of a PA named Sylvia. The police arrive and it is determined that she died of an aneurysm, how she ended up in the barrel Frank found her in is not known, although the police suspect cameraman Chuck. Apparently he had been providing Sylvia with nonprescription pain killers. The theory is Chuck found Sylvia shortly after her aneurysm and panicked, thinking she had overdosed. He could have hidden the body in the barrel not realizing it was to be used in an upcoming competition.
The Prissy Primers Challenge is canceled, for obvious reasons, so Veronica draws a team name out of a hat, to decide the winner. Blue Team is declared the winner, and each of the four team members, Joe, Mikey Chan, Mary Moore, and Gail Digby, will get to chose the next deprivation.
The four new deprivation is announced only an hour later, reading material, exercise equipment, hot water, and to blogger Bobby T's horror, the Internet.
After the deprivations are set, Veronica introduces two new contestants to Deprivation House, twins George and Georgina Tagart. No one on the show is to happy about more competition but that's what Veronica intended.
Frank is talking with Brynn but Joe isn't to happy about it either but decides to leave and do some work on the case. Upstairs Joe sees Mary doing a yoga workout and discovers that she might not be as weak as she appears. Joe notices Mikey acting strangely once again, and is going to follow him, when Ripley calls him.
He is still talking with Ripley, when he gets a whiff of smoke, looking around Joe sees smoke coming from an upstairs bedroom. Joe quickly swings himself up on the balcony of the room, looking inside he sees that the room is on fire and worse yet, Bobby T sleeping in his bed. The door into the room is locked, quickly Joe smashes out a window, and crashes into the room just as Frank arrives. Joe manages to get Bobby out of bed, and Frank soon puts the fire out with an extinguisher.
Others in the house soon arrive at the scene, and Bobby T declares that he is leaving the show, losing the Internet was bad enough but almost getting burned to death is the last straw. It is discovered that not only the smoke alarm was disabled, but the room's automated camera as well.
Frank and Joe meet up to discuss the fire, who could have started it? Not Brynn, Hal, Ann, or Ripley, since the first three were with Frank, and the later was talking with Joe before the fire started. Then Joe remembers that before Ripley started talking with him, he was trying to follow Mikey, who was sneaking out of the house. Could it be Mikey?
Before the brothers can question Mikey, Veronica calls all contestants down to the great room. Once every one is gathered in the great room, the next elimination is announced. Mikey Chan is deprived of winning one million dollars. A video is played showing Mikey sneaking around the house, like the Hardys have noticed. The last shot shows Mikey throwing away a candy bar wrappers. Mikey Chan has been sneaking junk food, ever since the contestants were deprived of it earlier in the week.
Frank and Joe still aren't certain that Mikey isn't the culprit, that is until a message is found, that reads, "Two more down, a dozen to go. Will YOU be the next victim?"
The message is written in Ripley's eyeliner and Gail accuses her of being a ringer. James disagrees saying that someone working for the show might try spice up the show but they wouldn't have done something like put broken glass in ice cubs. Ripley swears she isn't working for the show but admits that like Mikey accused her of she has been sneaking food. As it turns out Ripley has a eating disorder, so her parents asked the producers to keep an eye on Ripley's diet, they agreed, so when Ripley lost the challenge she was given food anyways.
Joe asks Frank to meet him outside in five minutes, Frank arrives late, saying it took him awhile to lose Brynn. Joe gets mad at Frank, and an argue ensues, in the end Frank says he doesn't want Brynn to get in the way of their mission, so he'll stay away from her from now on. But when Joe realizes that Frank is actually upset, and must really care for Brynn, he is to glad that Frank has finally gotten over his fear of girls, and tells Frank he's the one that will stay away from Brynn from now on.
Next Frank and Joe go to question Gail, they can't find her so Joe sits down on her bed and waits, suddenly a jab of pain go through Joe's thigh. He pulls back the bed covers and to his horror sees a rattlesnake. Frank grabs a bath towel of the dresser, throws it over the snake, giving Joe enough time to roll off the bed. Frank calls for the medics, over the intercom, then grabbing a nearby wastebasket, slams it down the snake trapping it.
Joe is writhing on the floor in pain, but tells Frank that if he hurries, he might be able to find the person who did this. Frank doesn't want to leave Joe, but can see his point, so as soon as Ripley arrives, he tells her to hold the basket down, he leaves.
Sprinting down the hall, Frank checks all the nearby rooms. All empty. Downstairs he sees Gail and Olivia, but Veronica is watching them, so he rules them out. Frank bursts outside to find Mary Moore pulling off a pair of gloves. Frank remembers she mentioned rattlesnakes before, and calls out to her, "So it's true – you really can handle a rattler!" Hearing Frank's damning words, Mary turns around and takes off across the grounds, with Frank in hot pursuit. Frank finally catches up with her, and tackles her to the ground.
Most of the pranks Mary admits to, but not the glass in James's ice water, the knifes that cut Brynn, or the fire in Bobby T's room. And when words are found scrawled on the wall, that read: "House of death", it becomes clear she might just be telling the truth.
This message requires your immediate attention.
This message will be erased in five seconds.
- Mikey Chan
- Anna Decter (mentioned only)
- Katrina Decter (mentioned only)
- Gail Digby
- Brynn Fulghum
- Olivia Gavener
- Fenton Hardy (mentioned only)
- Frank Hardy (Disguised name Frank Dooley)
- Joe Hardy (Disguised name Joe Carr)
- Ripley Lansing
- Mitch (mentioned only)
- Mary Moore
- Hal Sheen
- James Sittenfeld
- Ann Sommerfeld (Disguised name Silent Girl)
- George Taggart
- Georgina Taggart
- Wilson Tarlow (mentioned only)
- Bobby Tibbins (Disguised name Bobby T)
- Veronica Wilmont
- Bayport (mentioned only)
- Beverly Hills, CA.
- Hollywood, CA. (mentioned only)
- Indiana (mentioned only)
Businesses and organizations
- American Teens Against Crime (ATAC)
- New York Police Department (mentioned only)
- Deprivation House
- The Deprivation Chamber
- Forest of Blood IV (mentioned only)
- Gossip Tonight
- Little Orphan Annie (mentioned only)
- Serge Lutens lipstick
- Tubskull (mentioned only)
- Witness to Evil (mentioned only)
- Undercover Brothers #23 House Arrest