Mystery woman "Anna" was at the centre of Killing Eve season 1. 

During MI6's early investigation of "Villanelle" a.k.a. "Oksana Astankova," it was discovered that she'd murdered (and castrated) the husband of a woman named "Anna Aanmokoba."

The mystery woman's name was also the only thing to disturb the icy "Villanelle" in therapy. The relationship of "Anna" and "Oksana" captivated fans and produced a tense confrontation near the end of season 1. Here's what went down. 

Killing Eve: "Anna" - What happened with "Villanelle"?

It turned out that "Anna" was a former teacher of "Oksana" from her student days. They had an affair, but "Oksana" later killed her husband out of hatred. The crime sent her to prison, but "Anna" was wrongly told "Oksana" died in jail.

"Eve" then tracks "Anna" down and learns of her connection to "Oksana." Following the death of her husband, "Anna" was left traumatized and resentful. While in her home, "Eve" also finds an unopened note "Oksana" wrote to her former lover.

"Villanelle" then heads to meet "Anna" herself, possibly with deadly intentions. Both women pull guns on one another at "Anna's" apartment, but "Anna," unable to kill her former student and lover, shoots herself instead — leaving "Villanelle" visibly shocked.

Killing Eve: "Anna" actress Susan Lynch

Fans noticed that "Anna" had hair similar to "Eve's," one of the qualities that initially drew "Villanelle" to the MI6 agent. ("Anna" also warned "Eve" that she's the "type" that "Villanelle" is drawn to.) "Anna" may have been "Villanelle's" true love.

Susan Lynch played "Anna" in two season 1 episodes. The 49-year-old Irish star has had many roles in British films and TV and is a three-time IFTA Award winner. Some of her best-known roles are in films Nora, Beautiful Creatures, and the Downton Abbey movie.

Killing Eve: "Anna" was played by Susan Lynch

For now, it seems the "Villanelle" and"Anna" storyline has wrapped on Killing Eve. But you can continue to see actress Susan Lynch in programs such as Unforgotten and Save Me (both of which she appeared on in 2020). Killing Eve also enters season 4 in 2022.