Despite an outbreak of arson in Staircase, Wash., it looks for a while as if the dramatic high points of fire chief Mac Fontana's summer will be a fire drill at the local nudist colony and Fontana's run-in with a pistol-packing former actress with whom gossip soon, and inaccurately, links him romantically. But that's before there are two suspicious blazes the same night--and one of them, in the Cove Road house where Fontana's son Brendan is staying, claims the life of ancient Lorraine Gilliam (Staircase's first fire fatality in a century, Fontana tells a pesky freelance reporter, who promptly crucifies him in the Seattle Times). Could the arsonist be the bumptious hero who led five victims out of the Cove Road fire? The despised Staircase safety director who's had Fontana in his sights forever? The sometime volunteer who hadn't answered his pager ever since flunking the fire-department exam--until the recent arson rash brought him back? Or (as seems increasingly likely) is everybody in Staircase--from the actress's retarded son to the wealthy couple whose every possession seems combustible--getting into the act? Fontana's fourth (Morons and Madmen, 1993, etc.) features droll small-town backchat and some great fires--even if too many torchers do spoil the blaze.