But Long tells the story of finding hope after despair lightly and artfully, with self-effacement and so much gentle good nature that we forgot how sad she (and we) are. Her daring decision to put mushrooms rather than herself at the center of her story speaks to the sort of person, and the sort of narrator, she is.

An anthropologist originally from Malaysia, Long met her husband, Eiolf, while visiting Oslo on a college exchange program. They lived there happily and harmoniously into their mid-50s. “The Way Through the Woods” begins when everything changed, “the day when Eiolf went to work and didn’t come home.” Long is unmoored by a death that was as instant as it was untimely. What should she do now? Should she even remain in Norway?

At a loss, she enrolls in a course called Mushrooms for Beginners, something she and Eiolf had hoped to do together. She finds herself thrust into a world of zealots for whom “talk of fungi crowds out everything else.” (She makes many “mushroom friends” throughout the book, but often has little sense of their non-mushrooming lives.) She immediately sees the humor in the subject.

The mushroom course sponsor, the Greater Oslo Fungi and Useful Plants Society, “sounded like a sister organization to the Norwegian Women’s Hygiene Association,” she writes. “To be honest, I wasn’t sure what constituted a useful plant.” Is there also a society, she wonders, for useless plants?

But “mushroom outings gave me the push I needed to get out of the house and take part in life,” she writes. She prowls the woods for hours, learning how to spot elusive mushroom colonies and to identify dozens of different varieties of mushrooms — which kinds are rare, which are tasty, which are poisonous. She is invited by seasoned enthusiasts to secret mushroom locations known only to them, spots they guard with the fierce jealousy of a squirrel with a private stash of nuts.