Fire Chief Mac Fontana, with a growing record as a thorough, incorruptible arson investigator (Yellow Dog Party, etc.), gets a request from Seattle firefighter Diane Cooper--a plea to clear her from the accusations that she let three members of her ladder company (including her former fiancÇ) perish in the Ratt blaze. At first, no one wants to talk to Mac about the incident; then he's followed, shot at, lied to; and learns that the fireman hero who saved two trapped witnesses probably didn't deserve the credit. Meanwhile, the company chief is lazy, sexist, and racist; one of the dead firemen was terrified of smoke; and Diane's ex-fiancÇ hadn't spoken kindly to her since she passed the test for lieutenant and he was passed over to upgrade a black to the post. Furthermore, his brother Ben, now working security at the Belasco skyscraper, vowed to help him get even. All is resolved during a siege at the Belasco--in which hundreds are trapped by smoke and Mac and Diana save the day. Vivid descriptions of fire catastrophes, and widower Mac and his son Brendan are touching, as always--but the plot creaks and groans like floorboards about to cave in. Only middling for the series.