First in a projected trilogy about the aristocratic Heron family in ye olde England, with romance floating on a watery version of early 17th-century history. Orphaned at ten, Thomasina Heron is sent to her new guardian, Sir Simon of ""Goldhayes"" in Suffolk. There Thomasina will spend a happy young girlhood with her cousins: the Heron heir Simon; kind solid Edward; young James; friendly Lucy; and Francis--the ""different"" one who's imaginative, daring, apt to be cynical, who talks about unicorns and usually gets into trouble. (It's through Thomasina's intervention with formidable Great Aunt Elizabeth, from the Border country, that Francis' dog is saved from execution--though Francis is spirited away, out of family embroilments, with the old lady.) In the meantime Sir Simon has been making plans for Thomasina to marry, and well, since she's rather an heiress with lands in Oxford, Yorkshire, and Norfolk. But what a nasty choice! Creepy Sir Dominic Drakelon gives Thomasina a turn--so, after the death of Sir Simon, Thomasina squirms out of the marriage on the grounds of religion. (Dominic's a ""Papist."") Francis returns; he and Thomasina finally admit their love; young Simon and Francis are always at loggerheads--as are King Charles I and Parliament, with armies on the march. (Historical background here is rather cloudy.) Soon, then, Thomasina comes to the rescue of the Goldhayes friends and relations by leading them to her small castle Ashcott in Oxford, where subterfuge and tenacity (Thomasina visits Prince Rupert in the field to acquire more fighting men) ensure survival. But then come killings, a trek to Yorkshire, near-fatal illness for Francis, betrayal: Simon pops Francis into prison. And, when Francis is reported dead, weary Thomasina finally agrees to marry dreadful Dominic. . . until she uncovers Dominic's plot and hot-hoofs it toward Francis at the border, leaving baby Christopher with Dominic. A rum mix of stewed fact and modern idiom--but the dynasty romance here is sloppily good-natured, sure to find an easy-going readership; and little Christopher is clearly all set to star in Volume Two.