The two-level unit set for Strange Case represents the laboratory of Dr. Jekyll, a bedroom, a tavern, the streets of London, and the Stevenson home in Samoa. There are five actors with the three men playing two and, in one case, three parts. As lights come up we hear clocks ticking and wind howling and then the voice of Mansfield, an actor, trying different ways to say his lines about a door and a very strange tale. The UC door opens creakily and Jekyll enters. He takes a drink and wonders who he is talking to, saying that his life is a tissue of absurd soliloquies. He feels his face changing and looks in the mirror, actually a long oval frame, and sees Edward Hyde grinning back at him. Hyde says that Jekyll is now under his control and Jekyll backs onto the bed, covering his face with a pillow. Lightning and thunder and then the voice of Mansfield (the same actor who plays Hyde) speaking from the darkness like a stage director, asking for a bigger thunderclap and giving an example of a much bigger “NOOOOOOOOOOOOO!” for Jekyll.
The actor playing Jekyll now becomes Stevenson being awakened by Fanny, his wife. She tells him he was having a nightmare and sounded like somebody else. Stevenson says he is going to write down what happened in his dream. Jenny, a former lover, standing at the UR window frame on the second level, says that her letters must have gone astray. Fanny says that bogey tales are cheap and vulgar, but Stevenson says he has to write what the brownies tell him. When Fanny asks him where he was, Stevenson says he was drinking with Henley, and Henley, looking down from the UL level, quotes the opening lines of “Invictus.” After Henley staggers into the darkness down the left escape stairs, Stevenson tells Fanny that he will see less of Henley if she lets him write down the dream. Hyde enters DR and talks about the door that is connected in his mind with a late-night encounter with a little girl who ran into him and whom he trampled, twice, only to be accosted by her shrieking family who demanded money. He says he wrote a check but had to wait with them until the bank opened. He leaves, and Fanny, who has been reading the pages of the same story as Stevenson finishes writing them, asks why the girl was running. She says Stevenson wants her to be trampled, and he is writing an evil book. Stevenson insists that he must write what the voices tell him. When Fanny says he has a choice, he throws the manuscript into the fireplace, and, after Fanny leaves, Jenny looks down at the author drinking and says that once she heard “it” weeping.
Henley enters, asking Stevenson what he is writing. Stevenson replies that he is working on a horrifying tale about a fellow who’s been harboring a monster inside and finds a potion that lets the monster out to do whatever it wishes. He says the story brings up disturbing memories of a girl, a maidservant, he became attached to and whose letters he stopped answering. Jenny says she dreamed of a room full of mirrors and ticking clocks and a girl lying dead on the floor. Henley tries to warn Stevenson about women, making comments about Fanny, and Stevenson pushes him out the door. Turning from the door, Stevenson sees Hyde in the mirror but goes back to his desk to write.. Hyde asks what the name of “the little prostitute” was and Jenny pleads with Stevenson not to write the story or tell Hyde her name. But Stevenson does and Hyde says he should pay Jenny a visit. We hear footsteps growing louder, then the door creaking open as Fanny comes in saying that she met Henley raging on the stairs. She regrets her comments about the bogey tale and notices he has begun writing it again. After she goes out the door Stevenson speaks what he is writing about a crime of singular ferocity involving a maidservant.
Lights come up on a moonlit street and while Jenny watches and Stevenson writes, Hyde and Sir Danvers Carew (played by the actor who previously played Henley) meet in the street. Danvers talks about Oscar Wilde’s story of Dorian Gray, but Hyde, losing his temper, beats Danvers with his walking stick and continues beating him as he crawls off. Jenny screams and runs down the SR escape stairs. Stevenson is still writing when there is a knock on the door and Jenny comes in, telling him she saw a man murdered by Edward Hyde whom she has seen go in and out of Stevenson’s back door. When Fanny comes in, Jenny runs off, and Stevenson tries to explain her appearance to his wife. When she leaves, the actor playing Stevenson follows her out the door, only to return as Jekyll. Hyde looks out through the mirror, talks to Jekyll, and then steps through the mirror into the room. Jekyll complains that he has to spend most of his time trying to undo the evil that Hyde has done and tells him that he must go away. Hyde says that he is the true man and Jekyll only an artificial construction. Hyde says he is the hero of this particular penny dreadful and is a murderer because all heroes must be proficient in killing and doing monstrous things to women. Hyde says he is very glad to no longer be confined by the mirror. Jekyll says that Hyde is not real, that he, Jekyll, is really Robert Louis Stevenson. Hyde replies that Stevenson is a character in a play he is writing with Henley. Jekyll drinks the potion, lights swirl, orchestrion music plays like a mad carnival, and lights fade into fog.
Out of the fog, Stevenson hears Long John Silver (played by the actor who does Henley and Danvers) singing the “Fifteen men on the dead man’s chest” pirate song. Long John thinks Stevenson is Jim Hawkins and speaks lines for the parrot on his shoulder. When Stevenson thinks he is hallucinating, Long John suggests a vacation in Samoa and offers to help if “Jim” will let him look at the treasure map. He warns Stevenson about mayonnaise and about going into the cellar. Fanny knocks on the door to say that Richard Mansfield, the famous actor, wants to talk to Stevenson about making a play out of the bogey tale. Long John walks off into the fog; Stevenson opens the door and a voluble Mansfield enters, followed by Fanny. Jenny reappears at the SR window as Mansfield tells Stevenson that the Jekyll-Hyde story was made for the theatre, although some changes need to be made. The actor says he will play both parts, without tricks or makeup. Fanny thinks they could go to Samora with the money that Mansfield promises and Stevenson reluctantly agrees.
In the darkness we hear the door creaking open as Jenny enters carrying a lantern. She goes to Stevenson’s desk and the door creaks shut revealing Hyde. He wants to show her what is on the other side of the mirror and steps into the frame, pulling her, screaming, after him into the darkness. Lights come up DC on Stevenson and Fanny in Samoa. Fanny says she told the movers not to bring the mirror but they sent it anyway. When Stevenson goes off to bed, Hyde steps into the moonlight, tells Fanny that he is the one who makes her scream in the dark, and kisses her long and erotically. We hear wind and storm sounds as Fanny pulls away and Stevenson enters. She tells him that the other man is “here” and that he is death. Stevenson says she just dozed off and had a nightmare. Fanny goes in to bed and Hyde steps out from the shadows, telling Stevenson that he can never escape him, that he will always be on the other side of the mirror. Hyde says he wants everything Stevenson has and tells him he killed Jenny. Fanny comes back with a shovel and whacks Hyde violently again and again, calling him a monster. She tells Stevenson to bury the body in the jungle and, singing the pirate chanty, helps him carry the body off as the lights fade.
We hear birds singing and Fanny singing the chanty as lights come up on her making dinner. At his desk, Stevenson says he feels as if he murdered something inside himself, that some essential part is gone. Fanny asks him to get a bottle of wine from the cellar and as he goes out the door Jenny appears in the mirror, telling Fanny she shouldn’t have sent him to the cellar. Fanny puts a blanket over the mirror, threatening to break it into a million pieces and bury them in the back yard. Stevenson comes through the door saying that someone is in the cellar. Fanny says no one is in the cellar and asks him to make mayonnaise for their salad. Saying something is wrong inside his head, he pulls the blanket off the mirror. “There’s nobody in the mirror,” he says and collapses. Fanny holds him in her arms, calling for help, and Mansfield comes through the door saying that was not bad for a first rehearsal. He gives Fanny directions about holding Stevenson so his head lolls back with the mouth open. He praises her energy, suggests more desperation, and thinks the last bit should be played more downstage. He wants to include the line, “Be careful what you write. It will happen to you.” He tells her to save her tears for the audience. Fanny sobs that she wants to wake up as Mansfield rehearses his lines about the door and a strange tale that we heard as the play began.