Sheena Ferguson

Established identity and circumstances

Sheena is a senior intelligence official and Mavis’s long-term colleague, friend and recent lover. She has known Steve since infancy and would have become his guardian had Mavis died while he was a minor.

She is the person signing the letters to Mavis as “S.” She admits that she was in Berlin when Mavis was injured and left the scene after going to arrange a taxi. She considers this a professional error and says that an internal review has cleared her of misconduct, though her earlier conversation with Grace presents the matter as still consequential.

Desires, pressures and loyalties

Sheena wants to protect the intelligence operation, contain the Müller problem and preserve institutional control. She also loved Mavis and feels personal responsibility for Steve. Her professional and emotional roles conflict.

She wants Grace to cultivate Müller, partly because Grace has prior access to him and partly because she can be coerced through knowledge of her past work as an informant. Sheena explicitly threatens to expose Grace’s history and to damage her career if she refuses.

Agency

Sheena:

controls Mavis’s posthumous documents;
confirms Steve’s inheritance;
reveals Mavis’s relationship with her;
requires Steve to sign a secrecy undertaking;
reactivates Grace;
suppresses Steve’s BBC adaptation;
permits the stage production to continue because it serves an operational purpose;
treats Steve as a possible recruit but delays a final decision.

She is not merely an antagonist. She is emotionally affected by Mavis’s death and appears to regret the damage done to Grace and Steve. Her regret does not undo the coercive nature of her actions.

Position at the end

Sheena remains in command of the operation against Müller. She believes Grace’s relationship with Müller may be useful and that Steve’s play has helped maintain a false picture of British intelligence thinking. Her future relationship with Steve is open, but he now knows that she was both his mother’s lover and an authority capable of manipulating his life.