Most readers' familiarity with the work of Henning Mankell begins and ends with the 12 novels that comprise his series about the Swedish police inspector Kurt Wallander. To them, QUICKSAND, his posthumous collection of essays reflecting on his own life and subjects that range from archaeology to natural history to the relentless passage of time, may come as a surprise. If that's the case, this pensive and consistently enlightening book showcases Mankell as a writer whose talent transcended the mystery genre.

In January 2014, shortly before his 66th birthday, Mankell learned that the severe neck pain he thought was caused by a slipped disc was in fact the result of a tumor in his left lung that had metastasized into his neck. That dire news launched him on the reflections collected in the 68 pieces of this book. "I am in the middle of something. There is no conclusion yet," he writes in the first of them, announcing his diagnosis. Yet, he reminds us, "I am still completely alive, not somebody sitting by the side of my grave, dangling my legs over the edge."

Although there are brief allusions to Mankell's cancer treatment, QUICKSAND is not a conventional illness memoir. The short (most fewer than five pages) essays --- personal, political and philosophical --- span Mankell's fascinating, fully engaged life, one that has included, in addition to his ample writing in multiple genres, many years as the artistic director of a theater in Mozambique and extensive world travel. One interesting omission is any commentary on his controversial activism on behalf of the Palestinians, including his participation in the 2010 Gaza flotilla.

"We're fortunate [Mankell] lived long enough to compose this literary last will and testament, a book that's both encouraging and enlightening to anyone intent on savoring life's gifts."

Like any accomplished novelist, Mankell has a keen eye for detail and excels at mobilizing brief anecdotes --- some touching, others humorous or disturbing --- to make a larger point. He looks both inward and outward, at one moment summoning a dream as a nine-year-old from his childhood in the "snowy melancholy little town" of Sveg, in northern Sweden on the day he says he discovered his identity, at another lovingly describing performances by street artists in Italy and Argentina that never left his memory.

He's also an avid student of history, reflecting on disparate events like the causes of the plague in 14th-century Paris, the collapse of civilization on Easter Island or the periodic recurrence of ice ages, or revisiting the lives of Edward Jenner, discoverer of the smallpox vaccine, and little-known British abolitionist Thomas Clarkson in brisk surveys.

A subject that qualifies as one of Mankell's obsessions is nuclear waste, the only thing he says will be left of our civilization after an ice age projected to occur between 10,000 and 50,000 years from now. Beginning with a piece in which he describes how he learned about a site in the mountains of Finland that's being built to store that waste for 100,000 years --- "the troll hidden down there in its cave" in what he calls a "palace of forgetfulness" --- on no fewer than 13 occasions does he return to that ominous topic.

As a writer, he's especially concerned about how we'll communicate the danger posed by this toxic residue to whatever humans may exist thousands of years hence. "Is it in fact impossible for anybody to understand what a warning sign should look like in order to be effective when they know nothing about future people's language, culture and understanding of what is dangerous?" he asks. That subject dovetails with Mankell's fascination with ancient cave paintings. They are a phenomenon he examines both from the perspective of art and from the point of view of what their creators may have been attempting to communicate to those who would come after them.

QUICKSAND is a model for how a person whose reading and engagement with the world has been both wide and deep is able to lift himself out of his immediate circumstances, no matter how grim, and synthesize the wisdom gleaned from that engagement into a source of comfort. The book's pieces also reveal the mind of a man acutely aware of what it means to exist in the vast sweep of time, one who recognizes that any human life, no matter how rich it may seem, is inherently limited. "Nobody wants to be forgotten," he acknowledges. "But nearly everybody is."

Mankell's book ends about five months after his diagnosis, when his doctor informs him he has reached a "breathing space," one in which the writer was determined to live "in anticipation of new uplifting experiences. Of times when nobody robs me of the pleasure of creating things myself, or enjoying what others have created." That respite, sadly, lasted for too brief a time, as Mankell died on October 5, 2015. We're fortunate he lived long enough to compose this literary last will and testament, a book that's both encouraging and enlightening to anyone intent on savoring life's gifts.