A woman calls out from her apartment that she won't let someone down. She starts dancing around, opens a drawer full of something... then starts frothing at the mouth and collapses...

Maura looks at the video of the fire. Jane tells her to stop looking at the video. Maura says it's arson and thinks Jane should be worried. She points out that Jane was also hacked.

Maura gets a homicide call. Jane does not and checks her phone.

At the station Vince won't let Jane go with them. He wants her to go through files of people who might have a problem with her.

At the crime scene, Maura finds the body interesting. She has old tract marks, showing she used to use drugs. She has a butterfly tattoo. There is no evidence she was using cocaine at the time of death. There is a footprint suggesting a man was in the room with her.

Some cops are annoyed that Jane is taking a long time at the printer. She is printing all her threatening emails. The printer is out of paper.

Nina has been working on the video.She has found that the arsonist has a butterfly tattoo. Frankie asks if it is the victim from the scene he was just at. He recognizes the tattoo.

Jane does not have an email from the victim, Leanne Sampson.

Frankie says that Leanne had recently sobered up. She might be the arsonist. Nina cracks her phone and finds a lot of texts from someone named Hobert. Jane gets a call from Maura

Maura has been looking at Jane's door. The lock was picked by bumping the lock with a key over and over, which means it was done by a pro.

Maura meets with Vince without telling Jane. She did a psychological profile of the arsonist. She thinks Jane is in danger and should have a bodyguard. But Vince doesn't want to take Jane out of commission because she's the best chance of finding the arsonist.

Frankie interviews Hobart. He's a fellow addict who Leanne met in rehab. Leanne dropped him for some other guy with a lot of money. He never asked about anything because he knew she was just going to start using again.

Angela comes to see Jane. Jane has no patience for her. Angela is upset that Jane didn't call her. She knows Jane is in trouble. Jane denies it. Jane leaves to talk to Maura.

Maura says Leanne had five balloons of cocaine in her stomach. The balloons were punctured on purpose. The sixth balloon contained a watch. It was set for 5:26 -- within half an hour of time of death. The watch belonged to Jane.

Vince says they have until 5:26 tomorrow to find the killer. Jane enters the meeting and wants to know what's going on.

Vince tells her that she can't investigate when she's in danger. He's giving her a bodyguard. Usually he'd put the cop in protective custody. Jane must go home with the bodyguard. He wants to know about her living arrangements. He wants her to move out from Frankie's until this is over.

Maura comforts Frankie about Jane. They talk the case. He doesn't have much. The balloons are from a shoe store that closed 8 years ago. He's frustrated and afraid the killer will get to Jane. Maura thinks the killer might be a woman. That gives Frankie an idea.

The bodyguard is busy putting black tape on the windows. He takes Jane's clothes from her and tells her he can protect her better from the room she's cleaning out. Bodyguard won't let her order pizza. He offers to cook for her.

Angela comes to see Frankie. He tells her he has to go. She wants to know if something's going on with Jane. He tells her that someone's after Jane.

Jane is frustrated with the newspaper. The bodyguard makes her grilled Moroccan chicken instead of pizza. She loves it. The bodyguard tells her that he loves to cook. Angela shows up and bodyguard doesn't know who she is but lets her in after Jane tells him it's her mother (who she says is very dangerous and shouldn't be let in.) She is shocked that Angela says what's going on is not her business. She leaves the food she brought over and goes. She privately warns Boris not to let Jane get hurt.

Nina won't give Jane any info until Maura gives permission. She saw a guy following Jane twice. Jane knows who he is and says he's a good guy.

Head of the prison says Leanne Samson was a model prisoner so she knows nothing. Frankie meets with the jail psychiatrist. He thinks the death is tragic. Psychiatrist says that Leanne wanted guidance on how to turn her life around. He gave her support groups to go to. She had no regular visitors or ties to any guards or inmates. She was determined to change things for herself. She never mentioned Jane (psychiatrist thinks Frankie is talking about himself when he asks if she mentioned Detective Rizzolli)

Vince evacuates Frankie's building. Bodyguard tells Jane to get away from the window.

Nina charges Vince's phone for him. He gets out of the car.

Jane watches a bomb sniffing dog and the bodyguard tells her again to get away from the window. She eats the cookies he left for her.

Vince has a police car circle round the back. Ten minutes before deadline.

Jane is getting restless. One minute to go and she is on video chat with Nina and Frankie.

It is 5:27. Bodyguard says she will be freed in an hour. She looks at bodyguard's watch and realizes the watch was a code. She runs off to BPD without permission.

Vince tells someone he's on his way. He tries to get Jane to go back inside. She tries to tell him about the message. She insists on going back to the station because the message is for her.

Jane looks at all the evidence. She is not sure what the code is for. She yells at Frankie that if he doesn't want to be here he should leave.

Jane is near tears after Frankie leaves.

Frankie goes to see Angela. She gets him a beer and is surprised he doesn't even want to take a sip. Angela tells him that she's been taking every available shift to distract herself. She tells Frankie he and Jane don't know how to be scared for themselves and each other.

Maura offers Jane her couch but Jane doesn't want to sleep. She has too much on her mind. Hate letters, revenge emails, etc.  She doesn't know if her job is worth it anymore. It's very stressful for everyone. Maura says she would have loved to get an engineering degree or become a mystery novel writer. Or making up color names for JC Crew. But Jane can't think of anything else she'd want to do. Maura advises her not to make any decisions right now. She should lean into her discomfort. Jane leaves Maura's office promising she's okay.

Jane looks at the crime scene photos and evidence again. She takes everything off the board. Nina comes along. Jane says everything but the watch is in the past. She's still trying to figure out what 5:26. She asks Nina for a Bible. She starts going through Bible books in her head. She looks in the New Testament. She finds a Bible verse about taking everything. Nina tells her she's safe here. She realizes that the watch was a gift from Angela. She tries to call her but gets voicemail. She calls Frankie and tells him Angela's the target. Angela went home. She sends Frankie to find Angela. Vince realizes the reverse of 26526 is the penal code for kidnapping. 

Maura gets a call about a homicide.

Jane and Vince come into Angela's house, guns drawn. Jane walks in on Angela in a bathrobe. Angela knows already because of Frankie that Jane is being harassed. Jane breaks into tears and hugs her tight. Angela goes to make her some tea. Vince comes across Angela with his gun drawn.

Maura appears to be alone in an alley.

Frankie comes over.

Jane can't get Maura on the phone.

Someone grabs Maura as she is about to answer Jane's call...  She drops her phone.