Yury Lomakin, left, and Steven Carpenter in “Summerland,” set after the Civil War, by Arlitia Jones. (Photos by C. Stanley)
Theater critic

William Mumler’s claim to historical fame is as the “spirit photographer” whose portrait of Mary Todd Lincoln somehow included the spectral figure of her assassinated husband. Arlitia Jones takes that as a starting point for her inquisitive ghost story “Summerland” at Washington Stage Guild, where the three-character tale unwinds like an old-fashioned mystery.

The slightly dry first act belongs to Mumler and the skeptical lawyer bent on proving him a fraud. You could be watching a 1930s movie as Steven Carpenter sanctimoniously plays the highhanded lawyer Joseph Tooker, crusading to protect a hapless public from being swindled. Yury Lomakin seems too reserved as the earnest photographer, but there’s method in his gloom. Mumler’s faith in his “art” is tied to grief, so the men debate not only fakery, but also religion and metaphysics.

Luckily, a dark lady barges in to keep us guessing which way the story is going to lean, and the second act belongs to her. This is Mrs. Mumler, referred to as a spider and played with poise and menace by Rachel Felstein, whose voice has a deep luster to match her character’s slate silk dress (the costumes are by Sigrid Johannesdottir).

Part black widow, part Civil War spy, the flamboyant, seemingly shameless Mrs. Mumler plays the seductress and the savvy debater with Tooker. Meanwhile, director Kasi Campbell’s tasteful staging in the intimate Undercroft Theatre jolts your senses with muffled haunted-house ­effects. The dialogue spins with rational arguments, while the theatrics spookily knock the furniture around.

Yury Lomakin as William Mumler and Rachel Felstein as the menacing Mrs. Mumler.

The effects aren’t fancy, yet Campbell creates a persuasive mood. By the second act, the acting hits a level you might call restrained gothic amid the slightly pulpy feel of Marianne Meadows’s shadowy lighting and the subtle bumps and scrapes of Matthew Nielson’s sound design. Campbell never lets this descend into silly stuff. Instead, it shrewdly frames the lasting philosophical arguments prompted by Mumler’s peculiar true story.

Summerland, by Arlitia Jones. Directed by Kasi Campbell. Setting, Pancharee Sangkaeo. About one hour and 50 minutes. Through Oct. 21 at Washington Stage Guild, 900 Massachusetts Ave. NW. Tickets: $50-$60. 240-582-0050 or stageguild.org.