The Flying Scotsman ($23.95; Oct.; 320 pp.; 0-312-86364-0) A third installment in the adventures of Sherlock Holmes’s smarter brother Mycroft (Embassy Row, 1998, etc.). This time, Conan Doyle characters are plunged into an Agatha Christie situation when Mycroft and his amanuensis, Paterson Guthrie, are called on to escort the endangered diplomat Prince Oscar back to London aboard a train crawling with potential assassins.
