Old-style journalism vs. new-style politics in Boston-as veteran columnist Tony Owen, striving to keep his dying #2 newspaper alive, goes after the smooth Mayor (a Kevin White-ish figure) with increasing venom. . . and success. Tony, 42, gets the lead he's been waiting for from a disillusioned mayoral crony--who tells Tony to investigate recent building-fires down on slummy Duncan Ave. Were those fires (which killed one man) arson? And is a property-development company the culprit--a company backed by Mayor Connie Haydon's brother-in-law? So it seems. But the Mayor, an Irish would-be WASP who's actually only half-guilty (a nice shading), persuades publisher Elmer Granger of the Morning News (a.k.a. the Bruise) to play down the potentially hot Duncan Ave. story. (Granger, in fact, unlike Tony and editor Bobby Bantam, wants the Bruise to fold.) So Tony, muzzled, starts feeding the scandal data to his girlfriend Cynthia, a TV reporter--until the story breaks wide open: the shady real-estate types panic, beating up a friend of Tony's and kidnapping Cynthia; when the Mayor throws his brother-in-law to the wolves, his already bitter wife (loyal to old-neighborhood values) goes public with marital dirt. And the finale coincides with a visit to Boston by Pope John Paul II--an event which completely unhinges Tony's unstable brother Malachy, a derelict priest. (Both brothers are scarred by their mother's long-ago suicide.) This theological/psychological subplot, emphasized in the title, is less than convincing throughout; the contrived windup--Malachy's death leads to Cynthia's rescue (and to Tony's emotional growth)--is especially frail. But if first-novelist Hartnett stretches things out a bit too long and too busily here, he does a betterthan-solid job with the newsroom/backroom vignettes, the old-vs.-new Boston backgrounds, the Southie-to-Beacon-Hill characters. In sum: sturdy, atmospheric city-desk drama--less distinctive but more steadily readable, perhaps, than George V. Higgins' recent Boston-politics novel, A Choice of Enemies.