"They may not be the Dead Eels but they sure are one of Dunwall's most prolific smugglers!"
-Officer Manly Hotchkins, Wrenhaven Patrol.
One of the Runners' informants tips them off that a smuggling gang called the Sons of the Wrenhaven is intending to bring in a large shipment, though it up be up to the Runners to find out the exact details. During their investigations they'll encounter an Officer Rutherford Farrel of the Wrenhaven River Patrol. Though unbeknownst to anyone the smugglers are bringing in a few corrupted bonecharms and a certain witch from Serkonos.
When the Runners (and the River Patrol) try to catch the smugglers they found themselves (and the smugglers) being ambushed by the Hatters gang. In the chaos the witch slips away whilst the Runners run into a member of the Grand Guard from Serkonos.