It is a dark night in New York City and a woman runs out of the shopping store putting on shoes while she runs. Miranda Bowers runs by a television newscast in which two parents are speaking in front of the media asking for their child back. A few minutes later the heal of the shoe gets caught causing the woman to fall through window setting an alarm off.
The woman looks at the newscast and notices a mom asking for Bailey O'Dell back.
Stella Detective Flack and Mac are busy looking at the body of Miranda Bower who was 23 years old a receptionist at an investment firm she worked their part time. Detective Flack tells the two detectives that there aren't very many witnesses who can tell what happened. Flack discovers that the victims phone has been ringing off hook he doesn't have the heart to pick it up and tell whoever it is the victim is dead.
Stella determines the victim simply fell out of her shoe and suffered a broken collarbone. Mac also tells Stella to go home because she's been working three days straight and needs a break. Stella being determined as usual tells Mac she's fine. Mac tells her that this was an accident nothing more. There's no need for both of us being here. Mac says for her to get out of here. Stella heads home to her apartment when she hopes to get a good night's sleep.
Before entering her apartment Stella hears a little girl screaming "I wanna go home!" Bonnie Dillard tells Stella that she's having a slumber party, she tells Stella she is sorry and that she hopes Stella isn't kept up by the noise.
A few hours later a fire begins to start inside Stella's apartment building Stella quickly tries to get everybody out of the building. But finds a boy stuck in the apartment building with no way to get out Stella tells him to hold onto her and not let go.
Stella is busy getting Jason outside of the apartment where Bonnie is anxiously looking for him. Once Jason has found his mother Stella asks where Bonnie's niece is Bonnie tells her niece is with someone else.
Stella is busy looking at the damage to her apartment and discovers a picture of when she was in the police academy and also finds a note that simply says help me but Stella doesn't know who wrote it . Detective Flack comes to tell Mac and Stella fire investigators determined that the fire is arson and the point of origin is down the hall. There is also a victim they don't know who the victim is yet.
Sheldon takes a look at the body and tells everybody that because he or she was so badly burned it would be hard to find out who it was. Lindsay takes a look at and the apartment floor and discovers what appeared to be accelerant pour patterns and incinerate the furniture inside the apartment would have burned in seconds. Mac begins to think that someone else started the fire and the person who started the fire may have been the victim.
The victim they believe that started the fire was Sean Nolan who was arrested 5 years ago for arson. Stella thinks that maybe that's the reason why the sprinkler system was tampered with. Mac also says this particular victim doesn't fit the profile of an arsonist because they like to watch things blow up from outside or from a park.
Danny is busy making an omelet for Rikki who likely spent the night with Danny because she is wearing his shirt. Lindsay calls to ask him if he would like to go out to lunch Danny tells her that he can't do it right now he has things to do.
Before his shift Danny and Rikki are trying to figure out why they are still together in Danny's apartment they tell each other they just want to hurt to go way Rikki tells Danny that her son's death was not his fault.
Sid is busy watching the burned skin being removed from the head to hopefully better identify the victim Sean Nolan. Doctor Hawkes and Lindsay come into the morgue hoping that the medical examiner can give them more information on the cause of death. The only thing that can be determined is that the head their looking at is not that of Sean Nolan. Because the person didn't die in the fire so the head belongs to someone different now they have to figure out where the victim is and who she is.
Sheldon tells Mac and Lindsay that the body is that of a woman but they can't tell who the victim is and they only know that she died before the fire and all physiological evidence that helps identify somebody was burned off. Mac tells everybody that they're back where they started with the evidence they collected from the building. Mac tells everybody that the focus of the crime shifts from an accident to foul play. As they continue discussing which way they're gonna take the case Danny walks in late to work.
A very angry Lindsay is told to catch Danny up on the latest in the case. She hands him a computer which has a picture of the person they thought was the arsonist. Lindsay tells Danny way don't you read this. Sheldon and Danny both can't figure out why Lindsay walked away.
Mac doesn't want to guess if she died of natural causes. The autopsy on the victim suggests that she was between 30 and 40 years old. He instructs Danny and Lindsay as well as Sheldon to find everything they can to see if the victim's death is any way connected to Sean Nolan.
Adam and Stella are busy looking at a note that Stella found in her apartment Adam believes that they may have been written by a friend. Stella wonders why a friend would simply write a note saying help me rather than just simply call. Stella asks Adam to see if he can lift an ink imprint from the pen to see who might have written it. He tells Stella in a moment of humor that she can write better than she cooks. He was glad Stella is OK.
Sheldon is bound and determined to see if they can determine the victims time of death. He does so by bringing goldfish to the lab which were found in Sean's apartment. Sheldon figures that since the apartment was dark for two or three days the goldfish might be able to help establish a time of death for the victim. Sheldon theorizes that because it was dark in the apartment for two or three days the goldfish changed color because of no sunlight. Goldfish have something which allows them to change color.
Danny now having been caught up on the investigation thus far theorizes that Sean left the apartment for two or three days and then came back to set the fire. As they continue along that theory Detective Flack calls Sheldon and tells them they have the suspected arsonist in custody.
Sean Nolan is being interviewed by Detective Flack. Sean tells the detective that he was in Boston's at an insurance conference and didn't burn his own home Detective Flack doesn't believe the story and figures that he did it just to get excited by the fire. Sean continues to insist that he was not at home the day his apartment burned.
Mac, Lindsay and Stella are busy looking at a simulated floor plan which includes Bonnie Dillard's as well as Sean Nolan's.
Mac, Stella and Lindsay have constructed a fake apartment to see if they can see how the fire started. One thing bothers Lindsay though since Sean Nolan's apartment was furthest away why didn't his apartment suffer a lot of damage. She figures the fire may have started in the vacant apartment. Mac goes along with her line of thinking and sets the fake apartment on fire the first apartment wall was brick and really doesn't get the fire going. Unfortunately they really don't have much to go on as to how the fire started.
Mac, Lindsay and Stella head back to the Dillard apartment to see if they can find anything. They find a cigarette lighter indicating that body was a smoker but that doesn't indicate she started the fire. Mac gets very quiet and looks up at the air duct which was where the fire started because the fire was looking for air and Sean Nolan's apartment had an open window.
Back at the lab Hawks and Lindsay have analyzed the fingerprints from the lighter to come up with a problem. The prints found on the lighter were the fingerprints of Bailey O'Dell whose fingerprints had been registered with some kind of database.
As Stella realizes this she thinks back to the night when Bonnie told her of the slumber party and heard screaming. Stella realizes that it was right next door.
Stella is at the police station with Mac who is asking all sorts of questions about Bonnie Dillard like where she worked and what she did and then about Jason's school. She tells Mac she's only had hallway relationships with Bonnie and only moved into the apartment two years ago. A few minutes later Stella is busy sitting in front of the computer trying to describe the body. In the lab Stella and Mac are walking down the hall and Stella mentions that Jason was acting a bit differently. She tells Mac that she noticed a hole in the adjacent brick wall that led into her apartment which can see right through her bedroom.
She figured Jason was being nasty and wanted to watch her dress. Mac then tells Stella how he has been trying to figure out how to tell her to take a few days off to deal with the loss of her apartment he figured that would be a bad idea. A few minutes later Sheldon drops by and says that Bonnie called her insurance company for a large check written out that she would pick up later.
Stella mentions that this is an ongoing arson investigation and insurance claims wouldn't be processed for at least two weeks. Mac figure out quick way to get Bonnie to start talking, he tells Stella and Hawkes then maybe she could get her check from the bank faster.
Moments later Detective Flack is interviewing Bonnie who tells him that Bailey O'Dell was better off with Mrs. Dillard rather than her real parents. Bonnie mentions the she was told she shouldn't be a single parent that there should always be two parents in the relationship.
Detective Flack still gets nowhere in finding out exactly where Bailey O'Dell is Bonnie then decides to not tell the police anymore. Mac and Stella are watching the interrogation through a window Mac asks Stella if she believes if Bonnie is capable of doing anything. Stella tells him that if she'd been asked that a week ago or two years ago she might likely would have said no. Now Stella believes she's capable of anything.
Lindsay gets a possible lead on where Bailey O'Dell might be. She tells Stella and Danny she found a federally protected plant that was found on Bonnie's clothing because she is a florist. But Lindsay can't get anybody to talk about that because they could get arrested. Lindsay discovers that the plant is growing somewhere in New York illegally.
Mac Stella and Detective Flack all head to the flower shop where they believe Bailey and Jason are. They each look under the tables with rows of flowers. Stella finds the kids a few minutes later under the table covered up.
Stella interviews Jason whose real name is Austin. Stella accused him of doing something he didn't do and that he was only trying to ask for help. Jason wonders if he will go to jail because he started the fire and left the body of Marla Bronson in the apartment.
Stella tells him that he won't go to jail. Meanwhile Mac along with the parents has been busy watching the interview and tells the parents that he has been brainwashed into thinking that Bonnie was the better parent. He also tells them to go slow and that it will take time to trust the real parents again. The mother is just excited he is coming home.
We find Stella taking a leisurely walk possibly thinking about the case. She spots the local newscast updating everybody on the rescue of Austin. We leave Stella smiling.