You’ll have to hurry if you’re going to catch either or (I recommend) both of the plays now running in downtown Hartford. One was a sensation on Broadway last season and the other, a brand-new musical, is certainly headed there.

Venus in Fur, at TheaterWorks through Nov. 18 (860-527-7838, theaterworkshartford.org), is a play about a play about a book about an idea—an idea that David Ives’ play explores, exploits and explodes. It’s based on the novel of the same name by Leopold von Sacher-Masoch—the book that gave us the word masochism—about a man obsessed with the idea of being dominated and humiliated by a woman. The play imagines a stage adaptation of the book and takes place during an audition for the part of the dominatrix, conducted by the playwright/director.

The actress who shows up, late and flustered, is a blonde airhead with a kewpie-doll voice who doesn’t know the difference between “ambiguous” and “ambivalent” but somehow knows the script by heart and a lot of other surprising things. The part is many characters in one—mistress and master, Gidget and goddess—and Liv Rooth nails them all with an incredible vocal range, a quick-change emotional reach and a deliriously sensual physicality.

Venus in Fur, book and play alike, is a sexual power play, a see-saw of dominance and submission in which the whip hand keeps shifting. Rooth’s performance, er, dominates the show, but David Christopher Wells is hardly, well, submissive, convincingly showing us a strong man whose certainties fray as the teeter-totter tilts. Rob Ruggiero’s production deftly traces the power game, delivering both laughs and chills.

No S&M for the villainous hero of A Gentleman’s Guide to Love and Murder, at Hartford Stage through Nov. 11 (860-527-5151, hartfordstage.org), just good old-fashioned homicide. He’s Monty Navarro, a shabby but respectable young Englishman who suddenly discovers he’s eighth in line to inherit an earldom and a fortune, and proceeds to slaughter his way to the front of the queue.

The musical is based on an Edwardian-era novel and the classic film it inspired, Kind Hearts and Coronets, in which Alec Guinness played all eight of the ambitious young man’s ill-fated cousins. Here the octet of blue-blooded victims is played with thrilling virtuosity and panache by Jefferson Mays. They include a tweedy country squire, a toothy vicar, a matronly do-gooder, a stuffy banker, a hairy-chested body-builder and a melodramatic diva.

It’s an equal pleasure to watch Ken Barnett move smoothly through Monty’s transformation from ordinary bloke to gimlet-eyed schemer to debonair aristocrat. Likewise Lisa O’Hare and Chilina Kennedy as Monty’s conflicting love interests, the commoner he adores and the heiress he covets. Alexander Dodge’s set ingeniously recalls the music-hall era with a gaudy proscenium stage nestled into the larger setting.

The score, by Steven Lutvak and Robert L. Freedman, who also wrote the smart and efficient script, is a witty, tuneful pastiche of styles, with echoes of Noel Coward, music-hall ditties and a dash of Sweeney Todd. A Gentleman’s Guide is a rarity: a show that puts a fresh face on musical comedy conventions, satisfies the ear, the eye and the funnybone, and appeals hilariously to the peculiar human fascination with violent death.•

Contact Chris Rohmann at StageStruck@crocker.com.