ENCHANTED ISLANDS

By Allison Amend

306 pp. Nan A. Talese/Doubleday. $26.95.

“That my life will be of interest to readers I dare not assume,” Frances Conway explains early on in this novel based (somewhat loosely) on the published memoirs of a survivalist and her husband. “But it is an unusual one, and for that reason alone record should be made of it.” Smart but not brilliant, plucky but not vivacious, Frances is born in 1882 to immigrant parents in Duluth, Minn. — a town she runs away from as a teenager, both goaded and accompanied by her damaged, alluring best friend, Rosalie. Set to move through the world together, the friends part after a scandalous sexual treason (hair braids are involved). Frances travels west in pursuit of professional satisfaction, where she rubs uncomfortably up against her solitude only to reunite with Rosalie decades later, outside a movie theater in San ­Francisco.

If that doesn’t sound to you like the first hundred pages of a novel purporting to be about a pair of married spies sent to the Galápagos Islands to monitor the behavior of potentially murderous Germans in the midst of Hitler’s rise, I’m not surprised. But Allison Amend’s “Enchanted Islands” isn’t concerned with packing its protagonist off to face exotic hardships and emerge a freshly insightful woman. This isn’t yet another novel about a woman “finding herself” in the wild; it’s an endearing chronicle of female friendship and evolution in the early 20th century.

We first meet Frances and Rosalie as hobbled old women living out their final years at the same nursing home in the mid-1960s, bemoaning the gloppy food, giggling over a “second-rate magic show” and bickering over riding in the front seat on outings with Rosalie’s son. Sweetly bound to each other as companions, they have a relationship that feels more like a marriage than a friendship, with its daily irritations and unspoken gestures of intimacy. First we see them as young girls, and then as middle-aged women forced into different social strata by religion and wealth; still, their every movement circles back to the primacy of their friendship. When Frances and Rosalie aren’t together, it’s the other they’re thinking of, acting for, wondering about.

All of which makes Frances’ “real” marriage, constructed by the military as a cover for her husband’s spying, look even more like the dummy show it is. Tied to each other by the bonds of militaristic necessity, Frances and Ainslie Conway develop a sweet affection and a working friendship. But marriage isn’t the life-sustaining partnership that Frances needs to thrive.