This adventure presents some interesting quirks, and is best run for a group of characters who have already become well-known in the area through particpation on earlier adventures.
It begins with some unseasonal bad weather, storms so severe that waterborne traffic has ceased. Although it doesn't suggest this, if you are running this as part of a campaign set in and around Rybalka, you might want to have the bad weather start during the previous adventure rather than suddenly announce that it's stormy. When an experienced sea captain shows up dead, his battered corpse tied to a shipping crate and floating into the harbour, the characters are asked to investigate...
The adventure starts rather slowly although there is an interesting scene involving a potentially-hostile mob - and which occasions the presentation of ways in which you can handle a mob scene. One suggestion is to handle them as a swarm, dispersing when they reach a notional 'zero hit points' (although no damage is actually taken, unless someone starts a brawl).
Eventually, things get moving and the characters are in for some rough times at sea... and it is not plain sailing once they reach their destination, either. There are a few dangers and opportunities to gain information and items that may help along the way, and characters need to be wary: attacking first and asking questions later may leave them in the dark about what is going on.
Once they reach the end of their quest, the characters are faced with a number of potentially deadly traps and encounters. Finding their way to their ultimate goal will not be easy... but there are some delights along the way. The outcome is not clear, although there are quite a few suggestions about what could follow.
Presentation on the whole is at adventureaweek.com's usual high standard, although (particularly in the latter stages) there are long blocks of text with the crucial mechanical bits not very well highlighted; GMs will find that prior study is necessary tp run this adventure effectively. A comprehensive Encounter Index is provided, hyperlinked from the main adventure text and providing stats for both Dungeons & Dragons and Pathfinder rulesets.
Overall, this is a curious adventure. It has the potential to establish the characters as potent adventurers, advancing their reputation and renown far beyond what earlier adventures in this series might have gained them, yet it feels a bit nebulous and less satisfying and does not reach quite the heights of most of adventureaweek.com's work: guess I've been spoiled by their excellence in other works. The underlying concept is good, it falls down somewhat in the execution. Still, it could prove an interesting and quite different mission for an adaptable party - provided that they don't get too seasick in all the storms!
[4 of 5 Stars!]