|Affiliation:||Central Intelligence Agency|
|Played by:||Marin Hinkle|
|Last appeared:||The Ninth Circle|
Isabelle Barnes is a CIA Analyst and Elizabeth's close friend.
She worked closely with Henry and Elizabeth to uncover the secret behind Marsh's plane crash and the murder of George Peters. During "Whisper of the Ax", Elizabeth reluctantly had Isabelle arrested and taken in for questioning, as she suspected Isabelle of being the traitor that had allowed the undercover operation in Turkey to be compromised. In the following episode, it was shown that Isabelle had been cleared of suspicion, and that she was willing to continue helping Elizabeth in her investigation. However, after briefly helping Elizabeth out in Turkey during that episode, Isabelle never appeared again, apart from a brief mention during the Season 1 finale.
She attended Yale University.