After Piper is attacked by a Wendigo and is cursed to become one, Agent Ashley Fallon was on the case, as well as a hunter named Billy Waters, who had encountered the Wendigo before when the creature killed his fiancé, Laura. Billy stated to Piper that Wendigo fear fire and they consume human hearts, and he had gone to Fallon to explain the same to her. However, while doing so, Fallon flinched at the sight of the flame from Billy's lighter, revealing herself as the creature, much to Billy's surprise. After the revelation, Fallon turned and snapped Billy's neck, killing him.
On the final night of the full moon, the evil Fallon went on a stakeout with Andy Trudeau, while attempting to seduce him. Unbeknownst to Andy, Fallon transformed into the Wendigo and later nearly killed Andy, but she was stopped by Prue and Phoebe. The sisters faced two Wendigo, as one of them was their sister Piper, and Phoebe fired the last remaining flare from her flare gun. When it froze, they learned that it was Piper that the flare was aimed at, and Phoebe redirected it at Fallon, killing the villainous FBI Agent.