The legacy of Sherlock Holmes is a wide one, spanning genres. The Imposition of Unnecessary Obstacles and The Tainted Cup give two vigorous nods to Arthur Conan Doyle’s classic mysteries while embodying radically different tones: While the first is a cozy sci-fi whodunit with romance sprinkled in, the other combines the classic Holmesian ethos with the sort of existential threat epic fantasy can provide. Both novels, however, are tightly constructed celebrations of the mystery form.

The second in Malka Older’s Investigations of Mossa and Pleiti series, The Imposition of Unnecessary Obstacles rejoins Investigator Mossa and her paramour, the botanist Pleiti, as they investigate a series of disappearances around Valdegeld, the university community on the rings of Jupiter in which Pleiti makes her home. As they search for 17 missing students, staff and faculty, Pleiti and Mossa travel from the habitable platforms that surround the planet to Mossa’s childhood home on Io, one of Jupiter’s moons. All the while, the specter of their last case looms large in Pleiti’s mind, the conclusion of which shook her faith in both the university and herself. The Imposition of Unnecessary Obstacles is a delightful cozy mystery: engaging, concise and as focused on its characters’ relationships as it is on the puzzle itself. If that wasn’t enough, Older delivers a world that is detailed enough to be believable but sidesteps away from distracting technical issues that could bog down the story. While lovers of hard sci-fi might feel frustrated by some of the implausibilities of Older’s depiction of life in Jupiter’s rings, the fantastical backdrop not only enables a clever mystery, but also serves as a subtle reminder of what might be in store for humanity if we can’t get our act together about climate change and income inequality.

Despite those faint warnings, The Imposition of Unnecessary Obstacles is ultimately a warm hug of a book. Robert Jackson Bennett’s The Tainted Cup, however, is a shot of distilled paranoia. The city of Daretana is under persistent threat of magical contamination and attack from the massive Leviathans that stalk the waters outside its sea walls. When an officer of the imperial engineering corps dies in a way that is both gruesome and horticulturally intriguing, famed investigator and notorious eccentric Ana Dolabra is pulled onto the case. Ever wary of engaging directly with the outside world, she sends her new assistant, the young Dinios Kol, in her stead. Magically engineered to remember everything he ever experiences, Din becomes Ana’s eyes and ears, and as they dig into the engineer’s death, they find a trail of intrigue that threatens the safety of the empire itself. The mystery within Bennett’s latest novel is slow and methodical, unspooling subtly throughout its 400-plus pages. True to the promise of its epic fantasy backdrop, the novel spins the consequences of the murder into something bigger than any could anticipate. Bennett expands the scope of this story in a way that feels both natural and occasionally surprising, dazzling readers with both his imaginative world building and perfect pacing.

As with many homages to Sherlock Holmes, both The Imposition of Unnecessary Obstacles and The Tainted Cup are told not from the perspective of their singular investigators, but from the perspective of their assistants. Just as with Conan Doyle’s John Watson, both assistants are in many ways far more three-dimensional than their partners. Older’s Pleiti spends as much time thinking about her research and her budding relationship with Mossa as she does on the case itself. And Bennett’s focus on Din and his occasional misgivings about Ana are often more compelling than any depiction of Ana’s antics.

But even as both novels focus on the everyman features of their investigative assistants, they also continue the tradition of the idiosyncratic, possibly neurodivergent, investigator. Both Ana and Mossa are singular entities, their intellects unmatched by their peers and just as quixotic as Sherlock Holmes himself. While neither wakes up the neighbors at all hours of the night playing the violin, each will worm their way into readers’ hearts in similarly unlikely ways, whether it’s Ana’s tendency to question visitors about the smell of their urine or Mossa’s encyclopedic knowledge of every food stall in the greater Jupiter area. Their lineage is clear, and their prowess is unquestionable.