The Emperor Is a Time Traveler

Sean Chase and Roxanne Lowell time-travel to the Aethelgard Dynasty. They make soap, then spicy crayfish. They offend Tyrone Alden, the prime minister's son, by selling contraband salt. They trick Tyrone Alden into bankruptcy, and fend off the prime minister's attack with cannons. They discover the Emperor is also a time-traveler, who destroys their operation with a warship. Escaping death, they vow to challenge the Emperor.