The House Is a Business

The Sinister Secret of Saltmarsh reads like a haunted-house module. A town, a cliff, a mansion that moans at night. Most tables run it as a ghost story with a basement twist. That works. ACKS reads the same pages and sees a warehouse with a ghost story attached.

The town is not a rest stop. It has a market, a council, and a reason the locals have not burned the house down themselves. The smugglers are not random monsters. They have a route, a schedule, and a reason the goods move at night. The house is cover. The real operation is the same one the Slave Lords ran at a larger scale: inventory, payroll, and a quiet road that makes someone rich.

5E turns this into a mystery with a boss fight on the ship. ACKS sees reaction rolls that matter. A party that treats every crewman as a stat block misses the syndicate. A party that lets someone live learns who pays for the next shipment. The gold is still the plot. The house is just where the plot keeps its books.

You can clear the mansion and sail away.

Or you can notice that the town already knew something was wrong and chose not to act. That choice is a domain problem. If the smugglers vanish, someone else will take their place. The next syndicate will already know which houses in Saltmarsh keep their lights on after dark.