A Dead Liberty

Catherine Aird, Author Doubleday Books $12.95 (177p) ISBN 978-0-385-23554-9

Because a blow to the head has almost totally incapacitated detective inspector Trevor Porrit, detective inspector C. D. Sloan is obliged to take over a case involving the poisoning of a civil engineer. It looks to be fairly open and shut, until Sloan finds himself intrigued by the defendantshe won't say a word. Working under the dual purposes of finishing what Porrit started and doing the job the defendant's attorney would have done (had she consented to one), Sloan involves himself in a case that is not only outside of his general jurisdiction, but also nearly a year old. Aird ( Harm's Way, Last Respects is in fine form in her 13th novel, mixing the occasional red herring with the sporadic unexpected twist. Although one does tend to get lost in her countryside and its innumerable towns, her characters are charming, intriguing and just unique enough to be distinguishable without being bizarre. (February 6)