A scoundrel, cad and coward, George Macdonald Fraser's Flashman has done nothing but accumulate honors in his adventures in the service of the British Empire. In this 12th outing in the series, cumulatively titled The Flashman Papers, our reluctant hero finds himself at the center of General Robert Napier's Abysssinian campaign. It's another excellent opportunity to comment on the folly of the British Empire -- and, like all the books, a rollicking entertainment. It's not just the wit and fine writing that makes this series so pleasurable but also Fraser's fully realized sense of history.  (ETP37, $14.00)