1777: In the throes of the Revolutionary War, Landon Mansion is commandeered by British Lord "Butcher" Bedford.
He stabs Lucy Tarleton - who spurned his king and his love - leaving her to die in her father's arms.
NOW: After the day's final tour, docent Allison Leigh makes her rounds while locking up... and finds a colleague slumped over Bedford's desk, impaled on his own replica bayonet.
Resident ghosts may be the stock-in-trade of stately Philadelphia homes, but Allison - a noted historian - is indignant at the prospect of "ghost hunters" investigating this apparent murder.