A mammoth Elizabethan-era adventure/romance, set in 16th- century England, Spain, and France, in which a pleasantly diverting derring-do plot is clobbered by chunks of heavily researched authentica--artifacts, urban scenery, and, worst of all, forsooth, dialogue that, i'faith, must needs impede the pace, perforce, when slathered on overmuch. Kat Langdon learns that her adored, look-alike brother Nick is about to spy for Queen Elizabeth's ``Moor,'' the political-wizard Walsingham. Targeted as a spy for Spain, and for the powers there planning to restore England to Catholicism, is Lord Harrington, nÇ Justin Lisle, handsome enough to cause Kat a pang or two. During the second attempt to get the goods on Lord H., Kat, in boy's garb and scaling walls with Nick, is captured. Nick escapes but, his memory gone, becomes part of London's underclass, where he'll learn survival (and the lingo) and find a lover. But Kat is forced to accompany Justin to Spain, where she'll meet his beautiful and fierce ex-lover Margaret, who'll spirit Kat to a grandee (as a paramour), who, in turn, attempts to force Kat's favors by importing a particularly terrifying Inquisition friar. Justin gallops here and there on what Kat assumes is traitorous business (an assassination plot?), there are all sorts of nick-of-time saves, Kat is a Wonder Woman with weaponry--and, oh, yes, Elizabeth I appears twice, impressive and joshing weightily. A long, long first novel/historical adventure, somewhat unwieldy for its simple, agreeable trunk-hose-and-dagger plot. Mayhap for her next effort the author might rein in her estimable enthusiasm for arcane speech and put more bounce in the belles and boys.