It's billed as a time-travel romance, which is probably accurate if you want to slot books into strict little categories, like widgets or something. There is time travel, and there is a romance. And it's mostly set in 1815, ground zero for historical romance, thanks to the everlasting influence of Jane Austen and Georgette Heyer.
But it is also something of a thriller, with a slow reveal of crucial information and many twists and double-crosses. It's fun for former English majors because Ridgway is a (pseudonymous) professor of English lit at Bryn Mawr College and likes to scatter bits of Romantic and metaphysical poetry in the dialogue. And it's a delight for pop-culture junkies, because Ridgway has terrific fun with anachronisms ("Clear eyes, full hearts," says a 19th-century courtesan).
Every time-travel story has a different conception of how it's done. In Ridgway's, time is like a river—hence the title—that certain people with the innate talent can jump into and navigate with their emotions. Our hero, Nicholas Falcott, jumps from 1812, just as he's about to be brochetted by a French soldier at the Battle of Salamanca, to 2003, where he's taken in by a mysterious global organization called the Guild, whose minions tell him he can never go back. Instead, they give him piles of money and extensive pop-culture training so he can pass himself off as a 21st-century man. Until . . . ten years later, they summon him from his peaceful existence as an organic dairy farmer in Vermont for a special mission that requires his return to 1815.
Meanwhile, back in 1815, Nick's neighbor Julia Percy tends to her dying grandfather, who has a remarkable gift for stopping and speeding up time and who, just as he expires, warns her that she is in grave danger from people who want to learn more of his powers.
Naturally, the two stories overlap and intersect, and it will probably come as no surprise to anyone who has ever read a romance novel or seen a romantic comedy that Nick and Julia will fall in love and, in defiance of Regency-era conventions, have the best sex ever. (They put John Donne's early poetry to good use.) That frees up Ridgway to devote more time to the theory and practice of time travel—hers is at least as plausible as a plutonium-powered DeLorean—and, better yet, the mysterious workings of the Guild, as Nick and Julia find themselves, naturally, in deeper and deeper peril.
The River of No Return isn't flawless—Ridgway is a splendid writer, but not even she can render the Corn Laws exciting—but it is tremendous fun. As far as time-travel romances go, it's not quite up to the level of Diana Gabaldon's Outlander, but what is? (And if you have any interest in such things, or in 18th-century Scotland, pick that one up right away, but make sure you clear your schedule first, because it's absorbing as hell and also enormously fat.) Booksellers will probably be comparing it to Deborah Harkness's A Discovery of Witches trilogy because it's a fantasy-romance for people who aren't turned off by characters quoting poetry to each other and having involved theoretical discussions of their various magical powers (and because Harkness is also a college professor), but The River of No Return is way more fun.
It's also Ridgway's first book. That's sort of disappointing because it means there's nothing else of hers that you can go back and read. The good news is, she left enough loose narrative threads hanging at the end of The River of No Return that a sequel is practically inevitable.