Half a Mind

Hornsby ( No Harm ) brings back doughty California homicide detective Lt. Roger Tejeda and his wealthy girlfriend Kate for a sharp-witted thriller that leans hard on coincidence. In a grisly reprise of a series of sex crimes Tejeda investigated five years ago, the neatly severed head of a U.S. Marine is found on the beach. Did Tejeda put the wrong man behind bars or is a copycat killer loose? In an excellent twist, Tejeda is on medical leave and can work outside the law; the catch is that he's been felled by partial amnesia. Tejeda's palpable frustration as clues skitter around his aching head fuels the suspense. The pace is smart, the humor sly and the robust characters--from the drunken coroner to Tejeda's spacy ex-wife--spar with the dexterity of old friends. (Mar.)