The author: Dorothy Dunnett, born in Dunfermline, once a portrait painter, wife of Scottish media-to-oil grandee Sir Alastair; in 1961 she launched the Lymond Chronicles of historical blockbusters and followed them with her current House of Niccol sequence.

The book: Caprice and Rondo (Michael Joseph, pounds 16.99), seventh of the Niccol novels of early-Renaissance yarns. Ice-bound in Danzig in 1474, our merchant hero - now in disgrace - plots his options and uncorks an intrigue on the usual vast canvas. Poland, Muscovy, Scotland, Italy, Burgundy, Turkey and Persia all feature in a lush imbroglio of trade, war, high finance and espionage.

The deal: Dunnett's chronicles are where fantasy freaks migrate when they grow up. Stuffed with period finery and chessboard manoeuvres, her books' cargo of heavy-duty research leaves a legion of regulars with the warm glow of vicarious hard work. Dunnett studies all the sources and visits all the sites; in return, her flock trusts her to the tune of 650,000- odd sales for Niccol titles alone.

The goods: The cast-list alone of Caprice and Rondo runs to seven pages; most of this crew really existed (such as Uzum Hasan, "prince of the Turcoman Horde of the White Sheep"). Pedantry and melodrama entwine when the ice melts. Dunnett's multi-cultural panorama has never ranged farther (Tabriz to Aberdeen) even though - as ever - the Scots enjoy plenty of limelight. Spies, envoys and bankers all do their border-busting thing while sturdy matriarchs match them and the odd bodice or twain is unlaced (not ripped).

The verdict: Dunnett's prose never equals the splendour of her settings; fans won't care about that. In the tradition of cosmopolitan Scots, she can make the sheer diversity of her 15th-century world vividly real for a popular market. As respectable escapism for winter evenings, Niccol still leads the period pack.