Dr. Katrina Perrow, played by guest star Amanda Tapping, was a psychiatrist who treated Vincent Ingram. She was later kidnapped and used as the second host for Traveler 001. Her body was abandoned when 001 switched hosts for the second time.
Dr. Perrow accepted Ingram as a client at an unspecified point in time. She agreed to Ingram's strict conditions: he was to be treated in his home, and Perrow was not permitted to bring any cell phones or electronic devices inside. Perrow believed she was treating Ingram for social anxiety and agoraphobia.
In their initial session Ingram lied to his new psychiatrist, telling her that his late wife and late business partner died of brain aneurysms. He was later able to open up to her and be completely truthful. During a session which lasted much longer than the allotted time, Ingram confessed to being a Traveler who was hiding from the Director.
Perrow listened patiently as Ingram told his story, interjecting on a few occasions to clarify details or express her thoughts. She did not believe Ingram was really a time traveler from the future. She believed her patient was having delusions as a by-product of severe paranoia. She may have suspected him of killing Irene and Oliver, whose deaths Ingram blamed on the Director. At the end of their session, Perrow told Ingram that he needed medication and her therapy was not helping. Ingram persisted, saying that he needed someone to talk to who could guarantee confidentiality. Perrow was visibly shaken after leaving Ingram's house, so much so that she almost drove away without her cell phone or cash payment.
Some time later, Perrow contacted Ingram using her personal cell phone rather than the burner he'd provided her. She told Ingram that she was no longer willing to treat him unless he accepted the possibility of taking medication. Ingram angrily refused. Now fearful of her own safety, Perrow ceased all contact with Ingram.
Soon afterwards, Perrow was approached by Grant MacLaren. MacLaren told her that Ingram had begun to act on his "delusions." She reluctantly agreed to help what she believed to be an FBI operation to arrest Ingram - in reality an attempt by the Travelers to find his location. Ingram saw through the ruse immediately and kidnapped Perrow, along with her daughter Ava. Perrow was last seen alive in a ransom video sent to MacLaren and his team, where she instructed the five to provide videos confessing their identities as Travelers.
Ingram used his consciousness transfer device to transfer his own mind - that of Traveler 001 - into Dr. Perrow's body (offscreen). Thus the original Dr. Perrow was overwritten and Traveler 001 became Dr. Perrow.
In his new body, 001 took Ava and Taylor to a safe location, accompanied by his henchmen. Their car was ambushed and he suffered severe injuries. He was captured by Dawn and Michelle, two Faction members, who begged for his help financing their missions. Dawn revealed to 001 that his actions in the past effected the survival of Shelter 41, the origin point of the Faction, and that 001 himself ultimately becomes their leader. 001 was angry at having this information revealed to him, against his own orders in the future, but realized the Faction was not his enemy. He ordered his own forces to stand down when they came to rescue him, and the two sides began working together.
Dr. Perrow was ultimately abandoned as a host when 001 switched bodies once more, this time using Jeff Conniker.