Ever since the discovery of her diaries in the 1970s, Sabina Spielrein, a Russian Jewish woman who was treated by both Carl Jung and Sigmund Freud, has been a protagonist in search of a play—a quest that ended in 1996 with Willy Holtzman’s absorbing if flawed drama Sabina. Amid tall mirrors and red velvet curtains, Spielrein, at first catatonic, emerges from her shell to play word association with Jung, who helps her see that her fascination with Wagner (“I am the doomed maiden, ringed in virginal fire”) comes from her childhood experience of a pogrom. Before long Spielrein, “living proof of the talking cure,” is friendly with Freud and studying psychoanalysis herself. Marin Ireland makes a splendid heroine, charting Spielrein’s evolution from twitchy neurasthenic to soignée protégée to stalwart crusader for patients’ rights. And as the triangle’s other two sides, Victor Slezak, a complex and sympathetic Jung, and Peter Strauss, a cigar-chomping dead ringer for the Viennese doctor, turn in fine performances too. What’s weaker is the play itself: Although Holtzman keeps things lively with brisk short scenes, a compelling contrast between Jung’s psychic myths and Freud’s soulful science, and an increasingly agitated Spielrein, who begins to feel more pawn than patient, Sabina sometimes seems like an underdramatized circus of ideas—Michael Frayn without the piercing intelligence.