|Affiliation:||National Health Services|
|Played by:||Andrea Thompson|
|First episode:||"Day 3: 3:00pm-4:00pm"|
|Last episode:||"Day 3: 5:00am-6:00am"|
Before Day 3 Edit
Dr. Duncan was acquainted with Jack Bauer on a professional basis before Day 3. She tried to contact him after she learned about the death of his wife Teri, but couldn't reach him in his self-imposed isolation following Day 1.
Dr. Duncan and Jack Bauer were on a mission to find Kyle Singer, whom they thought was carrying the Cordilla virus. After interrupting Jack while he was trying to use heroin, she discovered he was addicted. After finding Sam and Helen Singer, Nicole and her team tested them. When the results came back, her partner demonstrated that there was no trace of the virus anywhere. Jack and Nicole then surmised that Kyle was infected before coming home from Mexico, making him a human time bomb for the release of the virus. After CTU found Kyle Singer, they put him inside the HAZMAT building and Nicole told Kyle that he would die. Later, Dr. Duncan found out that Kyle Singer was not infected with the virus, and called Ryan Chappelle. It was then uncovered that the initial threat was a sting operation in order to find the real Cordilla virus.
Nicole was called back after Marcus Alvers released the virus into the Chandler Plaza Hotel. She learned from Tony Almeida that Michelle Dessler was inside with no suit on when the virus was released. She gave her the test that proved she was not infected. Nicole helped out the Hotel staff and guests, but most of them were killed by the virus.