There are very few books in which an immortal clone debates the futility of existence with a dog— that is actually a reincar­nated giant grasshopper— and makes any sort of sense.

“Liminal States” by Zack Par­sons is exactly the sort of weird novel where it does.

All right, that’s selling the book short, but we’ll get to that. “Limin­al States” tells a story in three parts and in three different time periods: a feud between a lawman and a cattle baron’s son in the old west, a detec­tive noir story set in the early 50s and a pandemic thriller a la Michael Crichton’s “The Andromeda Strain” in a near-future dystopia.

The first third of “Liminal States” is a western novel, one that takes the utterly dark and violent road that Cormac McCarthy made famous.

After a train robbery goes horribly wrong, wealthy scion Gideon Long finds himself wounded and fleeing through the desert before stumbling upon a mysterious pool. The pool makes Gideon immortal, recreating his body from its depths whenever he dies.

Shortly after this, Gideon con­trives to hurl the sheriff that wound­ed him, Warren Groves, into the pool. Groves turns all of his skill at violence to brutally killing his counterpart at every opportunity. The two men hate each other, but are drawn back by the strange gravity of the pool.

Act two of the book takes place in Los Angeles in the early 1950s. Casper Cord, a duplicate of Warren Groves, is a private investigator who takes it upon himself to inves­tigate the death of a waitress who resembles his progenitor’s long-dead wife.

In true detective noir fashion, the detectives are hard-boiled and cyni­cal, the ladies pretty and scheming and the case is never what it looks like at the outset.

Casper finds himself out of his depth dealing with a seemingly bulletproof giant, a Gideon clone at the head of an industrial empire, and a conspiracy that the government itself is in on.

The third act takes us forward another 50 years or so, to a world in which pool duplicates make up a considerable part of the population and Los Angeles, the site of the relocated pool, is ground zero for a rapidly spreading and actively hostile fungal disease that alters its victims in horrific ways.

The enigmatic Gardener clan may be the only people who know what’s going on, but the altered Warren duplicates aren’t talking and seem to be pursuing their own agenda. Polly Foster, a new breed of duplicate, is appointed to escort a UN disease response team; Casper attempts to resume living in a world he doesn’t recognize after 50 years of incarceration; and Bishop is a Gideon duplicate trying to preserve the bottom line while under intense international scrutiny.

The entire book runs an undercur­rent of cosmic horror, the implication that humanity is an insignificant piece in a much larger game. While it is not explicitly stated until the latter half of the third act, the pool is implied to be anything but benevo­lent as early as when Warren Groves is first thrown into it.

The subtle wrongness only piles up as the duplicates begin to lose touch with their human origins as time goes on, performing acts without a qualm that would boggle the average person.

All told, “Liminal States” is well-written, well-plotted and perfectly paced. It manages to make each act feel like a complete story in itself while still building to the grand climax at the end of the third part. Characters feel alive, motivated by their own interests and not by the plot, and grow from their experi­ences.