Khaled Hosseini’s return to the literary market Tuesday will almost certainly be followed in due time by his return to the national bestseller list.And the Mountains Echoed, the new novel by the author of The Kite Runner and A Thousand Splendid Suns — both also set in his native Afghanistan and big hits, with more than 38 million copies sold — will likely be the the most remarkable page-turner that readers find this summer.Hosseini weaves a riveting, multilayered narrative told from different points of view but focusing on the complex moral choices his well-developed characters make in their relationships.The consequences are messy and unpredictable, like life itself, and “unconcerned with convenient symmetries.”The choices illustrate the capacity of the human condition to love and betray, even family, though Hosseini also artfully challenges readers to examine themselves.The reader gets there through a narrative that traces back to a family in the impoverished village of Shadbagh, where Saboor, a widowed father, remarries and starts a new family.Ten-year-old Abdullah, from Saboor’s first marriage, feels like an outsider. While his father and stepmother, Parwana, raise their new family, Pari, Abdullah’s 3-year-old full-blood sister and his only link to his first family, is all he has.The lives of these two change when Saboor faces the most selfish and selfless decision of his life: to sell Pari to a wealthy businessman and his wife in Kabul.Pari’s material fortunes change, but emotionally she is broken. She does not remember her former family, but she realizes something is amiss and is forced to live with the pitfalls of a self-absorbed mother held captive by her literary career and alcohol.Her mother represents the many outside the walls of fiction — and others in the book — who yearn to escape to reinvent themselves and find a new identity.Pari’s stepmother, in another life, also longs to escape rather than care for her paralyzed sister. But she decides to stay and do her duty, until her sister decides to take her own life.Pari is ultimately raised in Paris after her adopted mother leaves Kabul to escape her husband, who becomes incapacitated by a stroke.Despite all this hardship, Pari sets out on a career in mathematics, a profession that allows her character to escape the gray areas of living. Instead of arbitrary choices, math allows for black and white.As Pari says: “There was comfort to be found in the permanence of mathematical truths, in the lack of arbitrariness and the absence of ambiguity. In knowing that the answers may be elusive, but they could be found. They were there, chalk scribbles away.”The book takes off in different directions, but each character, through Hosseini’s storytelling, circles back to the fate of Abdullah and Pari, 58 years later in San Francisco, where Pari finds the answer to the last of her questions about the past.Bravo, Khaled Hosseini. Until we meet again, in Afghanistan.