When the days grow short and cold weather forces cranky people together in cramped quarters, certain persons often turn to thoughts of getting rid of all the other people and having the fireside to themselves. Those certain persons are, of course, mystery writers. Luckily for the rest of us, their homicidal urges have been channeled into the creation of a baker's dozen of stories of Yuletide murder by such mystery writers as Elizabeth Peters, Robert Barnard, John Malcolm and Charlotte MacLeod herself.