Inspector Brant is back is back in the fifth novel in Ken Bruen's London-based cop series, Vixen.

For the Southeast London police squad, it's rough, tough, dirty business as usual. The Vixen, the most sensuous, crazed female serial killer ever, is masterminding a series of lethal explosions. She is unpredictable, wild, angry—and the cops don't even know she exists.
Meanwhile, Inspector Roberts is helpless to stop the explosions and his subordinates aren't doing much better. Brant is consumed with an even-bigger-than-usual mean streak, and fast-rising Porter Nash finds himself facing serious health problems—everything to do with needles. PC MacDonald is determined to soldier on, whatever the cost, and the career of a new addition to the squad, WPC Andrews, starts spectacularly but with Falls as her mentor she's not expected to last long. At the top, Superintendent Brown is close to a coronary, and arresting the wrong man in a blaze of publicity is only the beginning of his problems.
If the squad survives this incendiary installment in Ken Bruen's blazingly intense series, they'll do so with barely a cop left standing.