If you like your psychological suspense stories awash in atmosphere, drenched in dread, positively soaked through with sinisterness, “Palace of the Drowned,” by Christine Mangan is for you. The setting is Venice in the fall of 1966, the site of a real-life historic flood in which water levels rose over six feet — a consequence of high tides combined with three days of heavy rain and a sirocco wind that wouldn’t quit. (Such catastrophic flooding — now ascribed to climate change — occurred in Venice once again in 2019.)

Electricity, phone and gas lines shut down, the first floors of residences were underwater, and the city was isolated for a time from the outside world. In mystery fiction, this kind of extreme weather situation is what’s known as “the dark and stormy night” gambit.

As she did in her 2018 best-selling debut novel, “Tangerine” (set to be a film starring Scarlett Johansson), Mangan focuses her narrative on a slow-building, intense relationship between two women. Frankie (Frances) Croy is a middle-aged British writer who enjoyed a smashing debut years ago, but whose subsequent novels have never matched that early success. In fact, when this story opens, Frankie has retreated to a wealthy friend’s vacant palazzo in Venice to lick her wounds and hunker down to work. Some weeks earlier, a blistering review of Frankie’s most recent novel propelled her into inciting a very public brawl at a London book party. Frankie desperately needed to flee London and salvage her tattered reputation.

As she settles in, however, Frankie becomes increasingly convinced that a mysterious presence also inhabits the supposedly empty palazzo, whose inauspicious Italian name translates into English as, “Palace of the Drowned.” Since she knows no one in Venice, Frankie’s paranoia thickens like the shadows in the corners of the palazzo’s dusty rooms.

One day, though, as she’s walking near the Grand Canal, Frankie’s uneasy solitude in the foreign city is suddenly broken when a hand reaches out of the crowd and grabs her wrist. That hand belongs to a young woman, also British, who claims to be an acquaintance. Frankie is uncertain. Here’s a sliver of that momentous first meeting:

“I knew it was you,” the girl cried, pulling her close, into something that would have resembled a hug, had Frankie’s body yielded to the movement. “Oh, God, it’s been ages, but I knew it was you.”

“Do we know one another?” Frankie asked, stepping back.

“The girl’s hands flew to her face and she laughed. “Oh, goodness, you don’t remember.” . . . .

“You’re not Diane’s daughter?” Frankie inquired, the vision of a schoolgirl dragged in to meet her vivid in her mind. . . .

The girl’s face brightened. “You do remember! Oh, I’m so pleased.”

“Yes,” Frankie replied, allowing a tight smile. In her memory the girl had been blonde — but perhaps she was wrong.

That “girl,” whose name is Gilly, happens to be a budding writer who is well acquainted with both Frankie’s work and Venice. In the ensuing weeks, Gilly proceeds to drag a somewhat resentful, somewhat grateful Frankie through the city’s labyrinthine passageways to cocktail parties and the opera.

The ingeniousness of “Palace of the Drowned” derives from Mangan’s great skill in stirring up carefully calibrated doubt about everything and everyone. Was that initial meeting by the Grand Canal a trick of fate or did Gilly (who may or may not be a stalker) engineer the encounter? Is Frankie right to be suspicious or is she simply becoming more and more of the madwoman in the palazzo? And, is the palazzo really haunted or are Italian mice just particularly noisy? The ground of truth in this story is as unstable as its watery setting.

Mangan’s narrative structure, especially in the dead center of this tale, can sometimes feel a bit waterlogged, a little too bogged down in its own clever ambiguities. But the pace picks up as the historic storm of 1966 gathers force. Mangan, who has a PhD in English with a focus on Gothic literature, clearly revels in describing the claustrophobic terror of the storm:

“Frankie, entombed in the palazzo, sat and watched as the skies grew darker. The water below had taken on a metallic sheen — oil, she realized. . . . Various bits of debris floated by. A sofa, a suitcase. Planks of wood. Bolts of fabric.”

In a melodramatic climax worthy of the opera that Frankie and Gilly attend, tears, accusations and confessions fly free; so, too, do precious manuscript pages that sink down beneath the rising waves of the canal that borders the palazzo. Like so many other recent suspense stories, “Palace of the Drowned” ultimately turns out to be a tale about literary appropriation and the anxiety of authorship (see also Chris Power’s “A Lonely Man” and Jean Hanff Korelitz’s “The Plot.”) About her own commanding authorship, Mangan should have no anxieties: This is one damp creeper that will give readers renewed appreciation for the stability of dry land.

Maureen Corrigan, who is the book critic for the NPR program “Fresh Air,” teaches literature at Georgetown University.

Palace of the Drowned

By Christine Mangan

Flatiron. 272 pp. $27.99