In ‘The Pisces,’ a Woman and a Merman Fall in Love. Aquatic Erotica Ensues.

Melissa Broder wanted to meet underneath the fiberglass whale.

“I am #dtw (down to whale),” the 38-year-old writer wrote, suggesting a rendezvous in the Hall of Ocean Life, at the American Museum of Natural History in Manhattan. She thought being surrounded by ancient marine specimens might be generative when it came to discussing her new novel, “The Pisces.”

The book, due out on Tuesday, tells the story of a catatonically depressed woman named Lucy, also 38, who slumps around modern-day Venice Beach in California, aimless and alone. Unable to complete her dissertation on Sappho and dazed after a messy breakup, Lucy agrees to dog-sit for her sister who lives near the beach, hoping the brackish Pacific breeze might enliven her spirits. Instead, she gets the itch to toss herself into the ocean.

One night, she crawls onto a jagged rock jutting out into the sea foam, but before she can jump into the waves, she meets a comely young surfer. His name is Theo, and soon the two are meeting regularly under the stars — she on the rock, he always bobbing in the ocean. Lucy begins to wonder why she has never seen him out of the water, or even from the waist down. Then, the truth emerges: Theo is a merman. Yes, an actual merman, with flippers, who has been alive for centuries. The love between a human woman and a sea-bound man echoes the plotline of the recent Oscar-winning film “The Shape of Water,” but Broder infuses her narrative with a sardonic, youthful twist.

“The topics that interest me are the things that have been going on for a really long time and are universal to all humans,” Broder tells me over a light lunch (we were, of course, eating fish: I had salmon; she ordered branzino). “We’re all born, we all die, a lot — most, many — of us fall in love, many of us have sex. These have always been my obsessions." When asked about her Twitter account, she told me that she wanted to make it clear that she does not consider it a persona or a work of performance art. “I feel like a persona is a mask you put on, whereas So Sad Today is really this part of myself that I felt in my waking life,” she said. “People are like, are you always sad? And I’m like, ‘Well, there is a part of me that’s always sad, disturbed and anxious, and I need a channel for it.’ It doesn’t mean that’s my totality.”

After publishing the book of essays and a poetry collection titled “Last Sext” in 2016, Broder wandered around Los Angeles feeling somewhat adrift as to her next project. In New York, she had always written poems and essays on her iPhone as she commuted on the subway, but she found this method difficult in Los Angeles’ car culture. So, she began to dictate a story to Siri in the car.

“I don’t ever sit down at a desk and write a first draft,” she said. “I like to write in places where you’re not supposed to be writing because then there’s less pressure. So when I write now, I talk to Siri, and then my first round of edits is literally just trying to figure out what I said. Siri hears a lot of wrong stuff. Like, the other day she heard ‘That’s So Raven,’ and I didn’t say that. There are a lot of happy accidents.”

When Broder began to dictate “The Pisces,” she was reading Giuseppe Tomasi Di Lampedusa’s “The Professor and the Siren.” “It’s about a man recounting the story of his love affair with a mermaid, and I didn’t realize how dark it was,” she said, noting that she was drawn into the tragic stories of humans who had drowned themselves for merpeople. “Somany men have walked off the back of ships with rocks in their pockets. But why is it always a man and a mermaid? What if it was a woman, and what if it was set in Venice Beach, where I live?” She began to speak out three paragraphs per day, and within nine months, she had finished the book.

What makes “The Pisces” an experimental, exciting work is that Broder manages to knead together the genres of magical realism — Theo, the merman, is always presumed to be real; no apparitions here — and literary erotica, all with a bemused, wry detachment. Lucy and Theo make love, many times, and there is a great deal of detail in the novel about merman genitalia. The book would feel like smut if it weren’t so highbrow in its references (when trying on slinky underwear, Lucy muses that it “made me feel like I was part of some kind of ritual, a lineage, like Sappho’s all-female cult of Aphrodite.”). The sex scenes, which take place after Lucy convinces Theo to return to her apartment in a child’s sand wagon, are highly detailed. “We kissed each other with open mouths, sucking at each other like we were eating mussels,” Broder writes. She said that the explicit carnality of the prose was an essential part of the project. “I can’t write sex unless I’m turning myself on,” she said. “I wasn’t going to not show the fish sex. You got to have it. There may be merman fundamentalists who say I got it wrong, and I don’t blame them. I’m an interloper. I was always more into Pegasus, when it came to mythology.”

Alexis Washam, Broder’s editor at Hogarth, said: “When I first spoke to her, we had a lot of detailed conversations about the below-the-belt anatomy. We had to figure out where the merman’s loincloth went. Her fearlessness is exciting to me. She’s so naturally funny." When I asked Broder about “The Shape of Water,” she told me that she hadn’t yet seen it. “It’s simply that I’m not great about going to the movies,” she said, “The last movie that I saw in the theater was probably ‘Boo! A Madea Halloween.'” Still, she said, she is glad to be a part of the current vogue for aquatic love stories, both in print and on screen. She is adapting “The Pisces” into a screenplay for Lionsgate Pictures.

“The sea is totally a mystery,” she said. “The top of the ocean can be total chaos, but underneath, in the depths, there can be silence. Everything on the surface of the world is so chaotic right now, so there’s a desire to access a place that’s more uncharted.” In recounting one woman’s star-crossed relationship with a folkloric beau, Broder has crafted a modern-day mythology for women on the verge — if everything on the surface stops making sense, you need to dive deeper.