After entering NTAC, Tom is told by Diana that they "need to get started." Tom has no idea what she is talking about. He follows her into an interrogation room. Inside is Isabelle, who is dressed in a prisoner uniform, and in front of her is the syringe containing the substance that can kill her. Diana tells Tom that he has to do this, but he is hesitant. However, Isabelle also states that he must kill her because she may be bad and eventually kill millions of people. Tom reluctantly injects Isabelle with the substance. As she starts to scream in pain, Tom wakes up in his bed. He then goes to his closet and removes the syringe from a safe.
Meanwhile, blood is dripping into a sink, and it is revealed that it is coming from Shawn. His arms are covered in blood, and he is muttering to himself that he can't find the bug inside of him. He then walks off, stating that he's going to get an x-ray of his body. A little while later, as Maia is chasing a friend in the woods outside of the 4400 Center, she runs straight into Shawn and falls down. Her leg is injured, so Shawn volunteers to fix it. However, he instead begins draining her of her life! Luckily, employees of the Center are nearby and rescue her. A confused Shawn explains that he was trying to heal her.
As Diana later visits Maia in the 4400 Center's clinic, Richard takes Tom to Shawn's room, which is trashed. A worried Isabelle enters, wanting to see Shawn. Richard tells her that she can't see him right now. He then introduces her to Tom, who is nervous around her. Isabelle notices that he is staring at her and asks why he is doing so, but Shawn's psychiatrist returns from Shawn's bedroom before Tom can respond. The psychiatrist explains that Shawn is experiencing persistent and powerful auditory hallucinations, which are contributing to his delusions. His symptoms are consistent with the onset of disorganized schizophrenia. However, the diagnosis is unusual, since schizophrenia is usually gradual instead of sudden.
A little while later, Richard reveals to Tom and Diana about Daniel Armand's threat from the previous week, and he suspects that Armand has to do with Shawn's sudden illness. Diana promises to investigate but tells Richard and Matthew Ross that Shawn needs to be temporarily committed for the protection of others. Isabelle then enters and forbids them from locking Shawn up. However, Richard agrees to commit Shawn to a private hospital until everything is cleared up.
Elsewhere, Alana is speaking to a teen named Todd Barstow, who disappeared on August 29, 1995. She explains that since the 4400 children missed years from their family life, she can use her ability to allow them to relive their lost years. She offers to let him see his brother that was born while he was gone and to allow them to form a relationship. However, Todd replies that she should worry more about helping herself. Alana questions this, and he states that she has a "rage" inside of her that was created by the deaths of her husband and son. She asks how he knows about the hit-and-run accident, and Todd explains that it's part of his ability. As Todd then leaves to go back to class, he tells Alana that she has a right to be mad, since the person who killed her family is still at large.
At NTAC, Tom and Diana are investigating Shawn's illness. Although Diana puts out the idea that Shawn's schizophrenia may be normal, Tom still believes that the Nova Group did it. Meanwhile, at the request of Matthew, Richard meets in the woods with Zachary Gidlund, who disappeared on November 10, 1966. Zachary tells Richard that Jane Nance, a friend from quarantine, recently asked him to join her for dinner. During it, she asked him many questions, and he suspects that she was trying to recruit him for the Nova Group. Zachary gives him her name, and Richard thanks him. As they go their separate ways, Zachary is met by Isabelle. Elsewhere, Alana meets up with Todd and asks how he knew about her private thoughts. Todd explains that if someone that he's talking to is feeling something strong, he feels and sees it, too. Although he only sees fragments, he gives her the name of the drunk driver: Keane Driscoll.
Matthew catches Isabelle packing Shawn's clothes, and she explains that she is taking Shawn out of the hospital. Matthew tries to stop her from acting on the tip about the Nova Group and reminds her about her purpose, which is to eliminate the 4400! According to him, the coming catastrophe is actually the 4400. When Isabelle then starts to leave, Matthew warns her that she isn't ready to be alone and still needs his guidance. However, Isabelle begins using her powers to kill him. As he dies, she states that she no longer needs him and that it's "graduation day."
As Isabelle takes Shawn out of the Abendson Psychiatric Care Facility, NTAC locates Jane Nance, who disappeared on October 17, 1980. Jane's home is filled with animals, and it appears that her ability is to communicate with animals. There is a knock at the door, so Jane answers it. However, no one is there. When she then closes the door and turns around, she is face to face with Isabelle. Meanwhile, Alana stops by an Alcoholics Anonymous meeting that is being led by Keane Driscoll.
As NTAC enters Jane's home and finds her mauled to death by her pets, Richard learns of Matthew's demise, which doctors think was caused by a stroke. Tom and Diana talk to Richard and reveal that they suspect that Isabelle is connected to the deaths. He doesn't believe that his daughter could be responsible, but he promises to try to convince Isabelle to come back to the Center if she calls. Elsewhere, at the Alcoholics Anonymous meeting, Alana speaks to Keane. He reveals to her that he first started coming to the meetings about nine years earlier, after being involved in a car accident. However, he has little memory of the incident, and he has no idea that he killed anyone.
At NTAC, Tom tells Diana that they've put a trace on Shawn's and Richard's phones so that they can listen in if Isabelle calls. The two then talk about Isabelle. Diana reveals her fears, and Tom states that Isabelle is a whole new category of 4400. Agent Garrity then interrupts to tell them that Shawn's car has been located. As Diana leaves to go after Shawn and Isabelle, Tom stops by his home to get the syringe. Elsewhere, Isabelle takes Shawn with her to an auto garage owned by Jorge Molina, who disappeared on March 24, 1975.
Tom later returns home, finding Alana waiting for him in the living room. He informs her that Shawn's car was found abandoned. She then tells him about Todd Barstow and his abilities, as well as the fact that she knows the identity of the drunk driver. After Tom is told about her visiting the driver, to which he tells her to not do again, his cellphone rings. He answers, and a short while later, he arrives at Molina's garage, which has been burned to the ground. There are some burnt remains inside that are believed to be Molina. The origin of the fire is unknown, although Tom and Diana suspect that Isabelle caused it.
At the 4400 Center, Richard is awakened by a call from Isabelle. She promises that it's almost over and that Daniel Armand is causing Shawn's schizophrenia. She and Shawn are about to go to Armand's home. Afraid that she is in too much trouble, Isabelle asks if she will be able to return to the Center. Richard replies that he doesn't know, and he convinces her to tell him where she is going. NTAC intercepts the call, and Tom and Diana head to Armand's house. In Armand's basement, Isabelle has him tied to a chair. She then gets him to cure Shawn of his illness. Shawn returns to normal, with no memory of what happened. Not wanting to kill Armand, Shawn begins to get Isabelle to leave with him, but Armand reveals what Isabelle did to the Nova Group to locate him. However, she replies that she didn't exactly kill anyone; she merely turned their abilities against them. Against Shawn's pleas to stop, Isabelle begins turning Armand's abilities against himself.
Watching the now schizophrenic Armand, Shawn asks Isabelle why she did that. She explains that if they just left him, he could attack again. After being told that she would kill a hundred people to protect him, Shawn questions who she is. Before an upset Isabelle can reply, they hear NTAC arriving. Outside, Richard convinces Tom and Diana to let him speak to Isabelle before barging in. Richard soon arrives in the basement and learns that Isabelle wants to fight NTAC, so he tries to get her to come out willingly. She states that after all she did, Shawn now hates her, but he and Richard reveal that they're only scared of her. The trio then exits, and NTAC goes in to get Armand.
Later at NTAC, Tom and Diana watch as Isabelle is released due to a lack of evidence. Diana states her fears of Isabelle doing something even worse. Meanwhile, Alana shows Keane a newspaper clipping about the deaths of her husband and son. He doesn't understand why she's showing him this, but she reveals that he killed them while drunk. Keane claims that he's a different man now, but Alana states that she won't let him forget what he did. At the 4400 Center, Isabelle goes to her room and finds Tom waiting for her. He tells her that they need to talk. She agrees, so after revealing that some people want him to kill her, he asks her why they want him to. Isabelle sees the syringe and asks who gave it to him. Tom doesn't tell her who gave it to him, but he does say that the woman who did called her "evil." Isabelle then reveals what Matthew tried to get her to do and why she killed him; she also adds that she turned her back on being bad. Isabelle doubts that Tom can bring himself to murder, so she holds out her arm. He almost injects her with it, but he stops himself because he wants to make sure that killing her is the right thing to do.
At the 4400 Center, Todd shows Alana a newspaper article about Keane, who is in critical condition after being involved in an accident; his blood alcohol level was three times the legal limit. He fears that he caused it to happen, but Alana tells him that she did it. Elsewhere, Isabelle has an appointment with Dennis Ryland...Read the full recap