For the first two-thirds of Julian Barnes' latest book, the reader would be forgiven for thinking he or she was immersed in a strange but perfectly crafted history of — of all things — 19th-century Anglo-French ballooning. But then, after taking us high into the clouds, Barnes abruptly descends for the last third and confronts the subject of his own crash landing: the death of his wife. It seems a curious yoking of two disparate things, but it works. As Barnes says in his opening lines: "You put together two things that have not been put together before. And the world is changed." "Levels of Life" charts how three aeronautical pioneers changed the world and how one woman changed Barnes' world — until her premature death almost destroyed it.

The first two sections follow the exploits of amateur "balloonatic" Fred Burnaby, bohemian actress Sarah Bern­hardt and "uxorious" Félix Tournachon, and explain how such intrepid airborne adventuring meant "Aeronauts were the new Argonauts." Barnes goes on to track Tournachon's later breakthroughs as a portrait photographer under the moniker Nadar, and weaves a love story of sorts between Fred and Sarah — one in which the gauche Englishman misreads the coquettish Madame Sarah's signals.

As fascinating and as well-rendered as all this is, it is Barnes' last part which is the book's crux. His wife, Pat Kavanagh, lives a mere 37 days "from diagnosis to death." After being together for 30 years, Barnes suddenly finds himself sundered from "the heart of my life; the life of my heart." The same wordplay is at work in this section's title — "The Loss of Depth," rather than the other way around. Here we witness Barnes analyzing and measuring his loss, plumbing the depths to which he has sunk while attempting to define "the lost-ness of the griefstruck." Shock/surprises (he admits to having contemplated suicide — a bath, a glass of wine, a sharp Japanese knife) alternate with hard-won wisdom ("every love story is a potential grief story") in prose that is searching, angry, plangent and beautiful.

Love and grief, then, are the two motifs. Barnes can explain the former ("the meeting point of truth and magic") but the latter leaves him stumped — offering only, yet succinctly, that "Grief is the negative image of love." If, at the end, Barnes is still unable to make sense of his loss, he has at least edged a little closer to accepting it.

Barnes has resuscitated and fictionalized famous historical figures before. "Arthur & George" (2005) dramatized Sherlock Holmes' creator, Sir Arthur Conan Doyle, and his 2008 memoir, "Nothing to Be Frightened Of," gave us a meditation on mortality. In "Levels of Life" he blends the two but muses not on approaching death but death been-and-gone and the emotional wreckage. Only a writer of Barnes' stature could sublimate personal pain into something artistically exquisite.

We are all "groundlings" who aspire, he tells us at one point. "Some soar with art, others with religion; most with love." "Levels of Life" shows that Barnes still loves and longs, five years after his wife's death. The proof is there even before we start reading: the book's dedication, as with all of those that preceded it, says, "For Pat."

Malcolm Forbes has written for the Times Literary Supplement, the Economist and the Daily Beast. Born in Edinburgh, he lives in Berlin.