From the publisher's website:
Spies are common in the coastal cities, and the overlords depend on them to gain information about one another's plans. One such spy has gained vital information that could prevent a war and stabilize the entire coastal region, but his ship was lost at sea before he could deliver his message. Was it an accident, or could some evil force have an interest in preventing his information from reaching its destination? It's up to the intrepid PCs to find out! Drop this free online adventure by Robert Wiese into a coastal area of your campaign world. Suitable for four 8th-level characters.
Espionage is big business wherever political tensions run high. Such has been the case in Flundspoor, Blakemire, and neighboring port cities along the coast for some years now. Each city's overlord maintains spies in every nearby city to keep abreast of the other rulers' activities.
Various third parties living on and around the sea also have an interest in the welfare of the port cities. Some, such as pirates, simply seek to accumulate as much wealth as possible before their capture or retirement. Others endeavor to manipulate the rulers and the merchants and exert control over coastal affairs from behind the scenes. One in this latter category hopes to start a war between the coastal cities of Flunsdspoor and Blakemire. Not only can he profit directly from the war, but once the current overlords have been deposed, it should be easy to get his own choice of rulers into both seats of power. To achieve that, he must maintain a high level of distrust among the overlords. Thus, the spy who got word that Flundspoor wished to form an alliance with Blakemire could not be allowed to transmit that information.
The ship on which the spy had sailed, the Faithful Lady, was lost at sea under mysterious circumstances. Several different parties are interested in recovering the spy and his message, so it's up to the PCs to find him and set things right.