A Moscow cop is left out in the cold in this “impressive” Edgar Award winner for Best Mystery Novel (The Washington Post Book World).   When forced to choose between the law and the party line, Police Inspector Porfiry Rostnikov has a disturbing tendency to fight for justice, and that has won him no friends at the Kremlin. Now his enemies in the KGB have arranged a transfer to the lowest rungs of Moscow law enforcement, a backwater department assigned to only the most hopeless cases, one of which is about to take Rostnikov deep into Siberia.   A corrupt commissar has been stabbed through the eye with an icicle. A murder at this level should be a top priority, but Rostnikov gets the distinct impression that the powers-that-be would prefer this case go unsolved—and that Rostnikov not survive this Siberian winter.   “As always, Kaminsky provides a colorful, tightly written mystery . . . filled with twists, countertwists, and a surprise ending that is plausible and clever.” —Chicago Tribune