[s4e20] Lily -

: Emma nearly gives in to her darkness by attempting to kill Lily during a roadside fight, but Regina stops her.

: Emma and Regina track Lily to a diner where she is living under the name "Starla". [S4E20] Lily

: Lily reveals she has known the truth about her heritage and Emma's parents for years and has been seeking revenge. : Emma nearly gives in to her darkness

: Grapples with her "potential for darkness" and the guilt of knowing Lily’s life was ruined to ensure Emma’s goodness. : Grapples with her "potential for darkness" and

Emma discovers that Maleficent’s daughter, Lily, was the friend she knew in foster care. Realizing that Lily was born with the potential for darkness that was magically removed from Emma, she sets out to find her and reunite her with Maleficent.

For deeper analysis, you can check out reviews and recaps on sites like TV Fanatic and Entertainment Weekly. Once Upon a Time, Season 4, Episode 20: Lily