All her life, Mr. Hosseini writes, Pari has felt “the absence of something, or someone, fundamental to her own existence”: sometimes “it was vague, like a message sent across shadowy byways and vast distances, a weak signal on a radio dial, remote, warbled. Other times it felt so clear, this absence, so intimately close it made her heart lurch.”

As for Abdullah, he ends up in California, running a restaurant called Abe’s Kabob House. He and his wife have named their only child Pari, after his long-lost sister, and the younger Pari will dream of reuniting her father with his missing sibling. After her mother dies, and her father begins to suffer from dementia, Pari decides to postpone her dreams of going to art school to take care of Abdullah.

Creating a kind of echo chamber, Mr. Hosseini gives us an assortment of other tales that mirror the stories of Abdullah and the older Pari. There’s the story of their stepmother, Parwana, and her beautiful sister Masooma, who was originally supposed to become Saboor’s betrothed; the story of Parwana’s brother, Nabi, who becomes a caretaker and kind of brother to Suleiman, his ailing employer; the story of the brash, fast-talking Timur Bashiri, whose family used to live down the street from the Wahdatis, and his introspective cousin Idris, who both now live in California; and the story of a Greek doctor named Markos who has moved to Kabul (in fact, into the Wahdatis’ former house) to operate on children who have been injured in the war, and his childhood soul mate, Thalia, who now cares for Markos’s aging mother back home in Greece.

In recounting these tales, Mr. Hosseini shamelessly uses contrivance and cheesy melodrama to press every sentimental button he can. He has Parwana causing Masooma to suffer a terrible, disabling accident out of jealousy and resentment; and he has Markos drawing inspiration for his work in helping Afghan children from his sympathy for Thalia, who suffered a terrible facial disfigurement as a girl when she was attacked by a dog.

In the hands of most writers, such narrative manipulations would result in some truly cringe-making moments. That Mr. Hosseini manages (for the most part, at least) not only to avoid this but also to actually succeed in spinning his characters’ lives into a deeply affecting choral work is a testament both to his intimate knowledge of their inner lives, and to his power as an old-fashioned storyteller.