From his opening sections in Vienna, Wray moves outward into the family tree, following successive generations: Ottokar’s two sons, Kaspar and Waldemar, as they pursue diverging paths — the former resigned to his own mediocrity as a scientist, allowing the currents of larger forces to carry him along, while the latter (Waldy’s great-uncle and namesake) uses his intellect to carry out bizarre and horrifying experiments in Äschenwald.

Then to the United States and Kaspar’s daughters, Enzian and Gentian, who provide a portal to witness and experience the New York City of the 1960s, as the sisters become, through chance and fate, curators of their own sort of salon — less Vienna and more Bohemia — in a different but equally tumultuous era of history.

And finally to Orson Card Tolliver, Waldy’s father and a prolific writer of pulp science fiction whose greatest and most dubious mark on society is not his work but what it spawns: a religion, established by R. P. Haven, founder and “first listener” of the United Church of Synchronology. And also, lest it be forgotten, the husband of Mrs. Haven, the very addressee of the letters Waldy is writing from his bubble outside the timestream.

If this all sounds a bit complex, it is. Although complication isn’t necessarily bad in itself, and Wray’s previous work demonstrates his power and facility with complexity, here it doesn’t always feel anchored to a central idea or set of ideas. Wray is expounding a maximalist cosmology, sometimes exuberant, other times eclectic, at times verging on ornate. This comes at the cost of elegance. The one notable exception to Wray’s aforementioned precision is in his musings on the mysterious nature of time. Whenever in this book he veers toward this particular subject, his characteristic exactitude, his subtle, graceful, fine-grained prose is ever so slightly coarser. With a topic like time, the curve of diminishing returns is steep, and the continued expenditure of words often leaves one feeling not more clear but less satisfied. Poetry or science, or some amalgam of the two, can be fashioned into an instrument with which to make incisions, but with a concept as impenetrable as the nature of time, even the sharpest tools sometimes leave only patterns on the surface.

That’s certainly no embarrassment: Time is hard. In Wray’s case, even if his musings aren’t always fascinating, they are unfailingly thoughtful and gorgeously written. But that can be too much of a good thing — allowing a writer as good as Wray to substitute an exquisite sentence for a truly penetrating insight into our subjective experience of time, what it is like to be a finite being trapped in existence. At points, the inclusiveness and intellect of Wray’s novel crowd out the emotion. The plot overwhelms the story.

A related issue is that the book’s time travel often feels like an overlay, less a grand unified theory than a way to catalog a gloriously disorganized universe. Wray’s not aiming, presumably, to write sci-fi of the hard variety, and that’s just fine. However, it might be fair to say that his conceit requires a clearer buy-in, something to justify the omniscient narration, the direct address to Mrs. Haven. Waldy takes a leap out of the timestream, and we want to take it with him, but it would be useful to know what kind of device we’re using to do so.

But if the time travel doesn’t always feel essential, if the formal structure doesn’t always justify itself, these are complaints at the margins of an engaging and ambitious novel. This is a messy, chaotic story about a messy, chaotic century. And after all, Wray never promised a self-contained theory of chrononavigation. For this reader, at least, a novel is a success if it causes time to warp, to bend and deform, if it breaks time apart and puts it back together again in an interesting way. John Wray does all of the above, with wide-ranging intelligence and boundless verbal energy. Any experiment that Wray conducts is likely to be worth a reader’s time, and “The Lost Time Accidents” is certainly no exception.