Exactly halfway through Lapierre's The City of Joy, a missionary priest exclaims, ""Bless you, Calcutta, for in your wretchedness you have given birth to saints."" It is about several such saints struggling against overwhelming wretchedness that this account of life in the most squalid of Calcutta's slums, Anand Nagar (""The City of Joy""), concerns itself. In the telling, the protagonists find themselves overwhelmed in turn by a love and compassion as transforming and inexplicable as grace. The tale is initially absorbing, constantly disturbing and ultimately uplifting. Anand Nagar, according to Lapierre (who spent three years in Calcutta and Bengal researching the book), has the densest concentration of humans anywhere on earth. More than 70,000 Muslims, Hindus, Christians, Sikhs, Parsis and Buddhists are crammed into an area smaller than two football fields. Their average income is less than 10 cents a day. With one latrine for every 2,500 people and one fountain for every 3,000, sanitation is, to all intents and purposes, nonexistent. And yet, despite the crowding, the poverty, the scorpions, mosquitoes, rats and ordure, ""The City of Joy"" glows with human feeling. Orphaned children are immediately adopted by neighbors; religious festivals joyously praise a variety of gods; lepers are embraced and cared for; eunuchs (damned in Hindu theology) are revered. Lapierre traces the progress of a handful of idealists through this Indian Inferno-Purgatorio-Paradiso: the rickshaw-puller Hasari Pal; a Polish Catholic priest, Stephan Kovalski; Max Loeb, a young American doctor; Bandona, a beautiful Assamese nurse. Even Mother Teresa makes an appearance at the periphery of the narrative. Their alternating and, eventually, intertwining stories create a tapestry of human suffering, sacrifice and courage. As co-author (with Larry Collins) of such bestsellers as Is Paris Burning?, Freedom at Midnight and The Fifth Horseman, Lapierre knows how to tell a story. Unfortunately, the novelistic approach he has chosen occasionally casts an aura of Puzo or Cartland over individual scenes: "". . .all around them, blows rained down with redoubled savagery."" Or ""Then they surrendered themselves to pleasure."" Often, too, the translation by Kathryn Spink is awkward and inexact. Despite these quibbles, however, The City of Joy is more than welcome in a world that needs such reaffirmations of the human spirit very badly.