Annelise is the socially-adept and beautiful wife of the Deputy Undersecretary of Defense. She is originally worked by Philip under his alias Scott Burkeland, a Swedish intelligence officer. Philip’s conversation with Elizabeth at the start of the episode suggests that he has been working her for some time, without significant results.
As the wife of the Deputy Undersecretary of the Department of Defense, her source of information initially stems from overhearing her husband and his colleagues and friends’ conversations. She later uses a hidden camera strapped to her bra to take photographs of the home office of Caspar Weinberger; these are later used to scout the best possible location for a listening device.
Annelise is an skilled manipulator of men; even Philip appears taken in by charms at times, and seems to genuinely care about her. Annelise's romanticism and enthusiasm for being a spy sometimes gets the better of her; she is prone to melodramatic, emotional displays.
Although she is working him, Annelise falls in love with her target Yousaf, who initially returns her affections. However, when she comes clean with him about what she has done, he strangles her in a hotel room. Philip, listening through the wall next door, takes control of the situation and has Yousaf help him and Elizabeth dispose of her body. While he is helping Philip break the joints of Annelise’s body to fit her in a suitcase, Elizabeth takes a photograph of him.
Annelise’s affair, murder and the resulting photographs of Yousaf with her corpse are the blackmail that Philip uses to work Yousaf as an informant on Afghanistan. Although Philip maintains a straight face throughout the clean up and immediate aftermath of her death, the experience haunts him, as he correctly surmised Annelise wasn't "cut out for this.” He later rages at Gabriel that "I had an agent I slept with for three years. Then I got her killed. I broke her bones and I shoved her in a suitcase." This causes Gabriel to question if Philip is falling apart and able to handle what might be coming next.