Author Jeremy P. Bushnell's new novel understands that weird fiction is right at home in Boston

When the work began to build Boston’s first subway in 1895, laborers digging the tunnel under Tremont Street made a grisly discovery: human remains, and lots of them. So many that, according to writer Stephen Puleo, they began to carelessly pile the bones up in plain sight of passersby until, finally, a gang of pranksters made off with them and “paraded around the Common, led by one grinning youth holding aloft a skull as the others followed.”

Such a macabre tale may have inspired H.P. Lovecraft, who, in his short story, “Pickman’s Model,” imagined a horde of ghouls emerging from cracks in the floor of Boylston Street Station to devour the passengers stuck waiting on the platform. This probably more closely resembles the contemporary experience of MBTA riders than that of the character in Lovecraft’s “At The Mountains of Madness,” for whom the names of the Red Line stops serve as a calming mantra meant to protect him from insanity.

Dedham-based author Jeremy P. Bushnell understands that weird fiction is right at home in Boston — and that something isn’t quite right in those subway tunnels. His latest novel, “Relentless Melt,” is a fun, genre-bending revival of classic cosmic horror and detective fiction with a distinctly modern attitude.

The story begins in 1909 when Bushnell introduces us to Artie Quick: Filene’s Basement shopgirl by day, and aspiring detective by night. With her close pal, Theodore, an artsy eccentric and amateur magician, by her side, Artie is always on the lookout for an opportunity to hone her skills and better understand the criminal element that haunts the waterfront wharves and Back Bay’s back alleys. “Crime was not just something you did,” she thinks, “but a force in the world, a system, a tentacled thing that could reach out and envelop you, that could take hold of your family and simply rip it apart.”

Sporting close-cropped hair and a suit borrowed from her estranged, criminal brother, Artie impersonates a man in order to sneak into an evening criminology course taught by the august and paternal Professor Winchell. But after one class, the course is mysteriously canceled, and Artie and Theodore are confronted with a series of strange happenings that lead them to believe something sinister is afoot: an otherworldly scream emanating from the Common, a would-be kidnapper with a curved knife and a peculiar tree in the Public Garden that appears to have grown 10 feet overnight.

Bushnell does such a nice job of grounding the story in a kind of gritty realism — detailing Artie’s troubled home life, her struggles with gender identity and her stifled aspirations for something more than the world will allow her — that it almost slips by that Theodore is apparently learning real spells at the Boston School of Magic, presided over by the mysterious W.D. Gannett. For a time, it’s not clear whether Theodore is the credulous victim of a smooth-talking con man or if Bushnell is genuinely introducing magic into the narrative; by the end of the novel, however, there’s no doubt.

Artie and Theodore make a fun pair. They’re not exactly Nick and Nora Charles, but there’s a real affection between them that’s endearing. “Theodore glances at Artie, and in that glance, she can read an implicit dare: Go in… And she gives him a look back, with its own implicit dare: You first.” They’re a pleasure to read, two oddballs who are out of step with their time and only seem to fit in with each other. As they chase down their leads, they become embroiled in a conspiracy that brings together Winchell, Gannett, the chief of police, and the mayor, who have been covering up a terrifying secret: In the course of digging a subway tunnel to link Boston and Cambridge, some eldritch force has been loosed upon the unsuspecting city.

When the conspiracy comes to the fore, Artie and Theodore are little more than pawns being moved around the board by the major players. Though it befits their novice status, it would’ve been nice to see them flex their abilities a little more. And Bushnell’s tone, which is light and fun throughout the book, makes for an engaging read — but it’s a definite departure from the low-level sense of pervasive dread that marks most classic weird fiction. Sometimes, the lightness of the tone clashes with the severity of the action; it makes for a jarring transition when things get really weird.

That said, the time with Artie and Theodore is well spent, and the implication at the end of the book that there might be further adventures in store for the pair is exciting. With its well-tuned characters and imaginative approach to historical fiction, “Relentless Melt” succeeds in making readers wonder what else might be out there lurking in the unseen corners and crevices of the city, and eager to follow along and find out.

Jeremy P. Bushnell's "Relentless Melt" is out June 6.