ESCAPADE, by Jane Aiken Hodge, St. Martin’s Press, 231 pages, $18.95.

This period adventure-romance is a merry romp. Dashing through its pages are the intrepid, toast-of-London actress, Beth Prior, and Charlotte Cromyn, the runaway teen-ager and rebel heir to a banking fortune. Charlotte, restive under the persistent ardor of her childhood sweetheart, John Thorton, finds refuge with Beth and is ecstatic when she is allowed to accompany Beth, who sails to the island of Sicily to gather intelligence for the crown.

In 1804 Napoleon had declared himself emperor of France. Still hungry for conquest, he had invaded the kingdom of Naples, deposed King Ferdinand and Queen Maria Carolina, and crowned his marshal, Joachim Murat, king. When the banished royal couple fled to Sicily, the crown, which had stationed a British army there, warily waited for Murat’s next move.

The exile did not upset King Ferdinand. He shrugged and contentedly dallied with his mistress in a Sicilian retreat. The queen, mother of Ferdinand’s 17 children, was made of sterner stuff. She moves into a Palermo palazzo and began spinning plots to overthrow Murat. When word of her machinations reaches the British foreign secretary, he decides that in the role of spy, Beth could easily gain the confidence of the queen, while ostensibly filling an engagement at Palermo’s Theatre Royal.

Arriving in Palermo, Beth and Charlotte are quartered in a picturesque seaside villa. News of their presence spreads like brush fire and Charlotte (whose heiress status Beth had concealed with a pseudonym surname) is overjoyed when they are swept into Palermo’s glittering social whirlpool.

Male admirers — smiling, adoring, flattering — flock to the villa, seemingly with nothing more on their minds than the sport of paying court to the two beautiful English ladies. Beth’s offer to sing at the palace has been accepted enthusiastically and after her performance the queen seeks Beth out for her special attention. Everything seems to be working out according to plan, but Beth has misgivings. It was all too easy. She had captured her quarry, the queen, too quickly. Could it be, wonders Beth uneasily, that it was she who was the prey? But for whom?

Why was she the target of so many veiled, enigmatic remarks leveled at her by one of the queen’s daughters? Could it be that Signor Castroni, who slithered daily into the queen’s private chambers, had learned that Beth was a spy and had informed the queen?

A rapid succession of events is detonated in a terrifying explosion that puts the lives of both Beth and Charlotte at risk.

“Escapade,” a novel with a plume in its hat, churns with derring-do, historical fact and as-you-like-it romance. From this 25th book of author Jane Aiken Hodge, daughter of Pulitzer Prize winner Conrad Aiken, one knows in advance (from the infinite wealth of detail) that she finds the writing of historical novels her favorite pastime.

Bea Goodrich’s reviews are a monthly feature in the Books & Music section.