The Mystery of a Hansom Cab by Fergus W. Hume (Dover, $4). The very name "hansom cab" evokes the atmosphere of mystery in foggy London streets, but in fact, the first mystery to employ this popular Victorian conveyance was the now nearly forgotten creation of an obscure Australian clerk, Fergus W. Hume. After Hume published his book in Australia in 1886, it became a best seller in England and in America. Dated though it is in many respects, The Mystery of a Hansom Cab supplies a lively portrait of 19th-century city life down under.
Rumpelstiltskin, by Ed McBain (Ballantine, $2.50). A divorced lawyer has a torrid one night stand with a beautiful young rock star. The next day she is found murdered and her young daughter is missing, and the lawyer finds himself caught up in a manhunt.
Gypsy in Amber, by Martin Cruz Smith (Ballantine, $2.50). Gypsy magic, brutal murder and sacrifice, the underground antiques trade -- Martin Cruz Smith, the author of Gorky Park, works all of them into this hair-raising mystery, originally published in 1971.
People Versus Kirk, by Robert Traver (Dell, $3.50). If you enjoyed Traver's Anatomy of a Murder of some years ago, but don't remember it too well, you'll probably like this mystery, since it is in many ways a recasting of the same story.