Lorna Randolph is hired for the summer at Harrison Hall in Virginia, where Revolutionary-War reenactors provide guided tours of the elegant old home. She doesn't expect to receive a note and a kiss from a handsome young man who then vanishes into mist. Harrison Hall itself has plans for Lorna – and for Hart Harrison, her momentary suitor and its 18th century heir. Past and present are bound by pledges of love, and modern science melds with old skills and history as Harrison Hall takes Lorna and Hart through time in a race to solve a mystery and save Hart's life before the Midsummer Ball.