Montrose had come out for King Charles and Scotland was once again divided. Barbary Graham, the King's young relative, had been forced into a marriage with a man she hated. Always a tomboy, she wished to be like the strange Mrs. Frances Pierson, riding to war against the Covenanters with the Earl of Carnwath, dressed in armour and calling herself Captain Dalziel. Barbary tricks her husband, Drummond, into allowing her to accompany him as a groom, and from then on is involved in the realities of war.

It is only when she imagines she has lost everything she loved that she finds she has salvaged what is, after all, the most important thing.