Pathfinder Society Scenario #8-19: Treacherous Waves (PFRPG) PDF

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A Pathfinder Society Scenario designed for levels 3-7.

The Society believes that a powerful relic lies in the depths of the Plane of Water, yet the most recent expedition to retrieve it failed for mysteriously tragic reasons. It's up to the PCs to travel to the aquatic metropolis of Vialesk to investigate that ill-fated mission and overcome the forces determined to keep the truth from coming to light.

Written by Eleanor Ferron.

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Solid Mix of Various Gameplay Elements



I played Treacherous Waves in a play-by-post game with my “caveman shaman.” This review is based on that experience and reading the scenario afterwards. The scenario features some really interesting and well-developed NPCs, a rarely-visited setting, and plenty of opportunities for PCs to stretch their investigative, role-playing, and combat skills. In short, it’s an all-around strong scenario with only a couple of (relatively minor) flaws.


Treacherous Waves takes place on the Plane of Water in the air-breather city of Vialesk, with the PCs given transportation there off-screen. Waiting for them is a local aquatic ranger named Lileone who can have a very minor or surprisingly useful role in the scenario depending on how the PCs interact with her. At a minimum, Lileone tells the PCs that they’ve been summoned by a local Pathfinder agent named Zahra. But if the PCs make an effort to befriend Lileone, they can call upon her help in several ways throughout the scenario. It’s interesting and unusual to have something of potential significance happen before the briefing, and I like it. (I have absolutely no recollection of Lileone from playing it, and I think maybe the GM just skipped to the actual briefing).

Zahra herself is an Undine and the artwork of her is very good. GMs, show the players the artwork—it really helps with immersion! Anyway, Zahra explains why she’s summoned the PCs. Recently, she led an expedition out of Vialesk, planning to investigate a huge school of jellyfish called the Lambient Bloom. Zahra suspected that some fragment of the elemental lord Lysianassa’s power was hidden in the Bloom. But before they reached it, the expedition ran into streaming currents of toxic algae and were sickened and forced to turn back. Although most assume Zahra just got the group lost and stumbled into the algae, she thinks something very different: that the expedition was somehow sabotaged! She gives the PCs a list of four expedition members/suspects to question.

At this point, the scenario begins its investigative phase. The suspects include an ocean giant named Honoke, a brine dragon named Razethka, an aquatic elf named Tsomo, and a selkie alchemist named Yuka. It’s a great mix of creatures; very different than the PCs are likely to have encountered before, and thus a good opportunity for a GM to show off their role-playing skills. Beyond the four suspects, the PCs can also travel out to the site of the toxic algae and do some other things. I like how allowance was given to the GM to be flexible in different routes of investigation the PCs might take. My shaman PC’s ability to talk to sharks, for example, came in very handy and was supported by the scenario.

Interestingly, what the PCs don’t know is that they’re on a strict time limit once the briefing is over: something catastrophic is going to happen in exactly 24 hours! I normally really like time constraints as they’re a good way to add some consequences to the PCs’ actions and reward those feats or special abilities that speed up things like research or gather information checks. With this one though, I’m not sure if it’s really fair to hold the PCs to a time limit that they can’t know about until well into the session. My guess is that it probably doesn’t matter unless they decide, for whatever reason, to spend a lot of time resting.

Sooner or later, the PCs should start to suspect that Tsomo might be behind the sabotage. In a cool twist, Tsomo has been masquerading as his own assistant and is actually an evil vigilante malenti (essentially, an elf with shark features)! Tsomo is working for a big bad (who doesn’t appear in this scenario, but I assume recurs throughout Season Eight) to use alchemical supplies to create an explosion in Vialesk’s central forge, the Glass Pit, to crack the dome around the city and flood it! That’s the fate that awaits everyone if PCs don’t put things right within 24 hours, and is a suitably epic crisis that I’m impressed the scenario actually contemplates happening.

The first combat encounter of the scenario will be with either some sahuagin sent by Tsomo to eliminate an unwitting accomplice (the alchemist, Yuka) or against the same monsters inside Tsomo’s warehouse. (The artwork of the sahuagin on page 12 is great.) The warehouse encounter holds crates full of very volatile alchemical supplies, and setting the entire building on fire wouldn’t be hard.

The PCs by this point are expected to have discovered Tsomo’s plan and realize that he’s weakened the dome around the city in eight places. A series of skill checks, each taking some time, are necessary to find and repair the flaws. I don’t think this was integrated into the scenario well and felt very out of place when I played it.

Next up, the PCs are expected to try to defeat Tsomo, but he leads them on a Chase. Here, the PCs have to try to slow him down by using the environment against him, and there are some fun and clever choices. The GM is given some sound guidance on how to be flexible when PCs want to do things that aren’t listed as options during each stage, and the consequences of the Chase are satisfying (it affects how many reinforcements he’s able to gather at the climax). Chases can oftentimes feel very forced, but I think it was done about as well as possible in Treacherous Waves.

The big final battle takes place on a weird ring that surrounds a pool of water (and portal). There are sharks in the center pool, while Tsomo and (potentially) some sahuagin allies stand on the ring. I remember playing the scenario and wondering what the heck the sharks were for, as it was obvious that as long as the PCs stayed out of the water, they’d be no threat. After reading the scenario, I realized the GM had completely missed a periodic hazard that threatens to knock the PCs into the pool. It would have made the final battle far more exciting, and is a lesson not to always blame a scenario for experiences at the table. Apart from that possibility, for a scenario set on the Plane of Water, there’s actually very little need to have skill in Swim or the ability to breathe water. It’s somewhat disappointing, even though I acknowledge that scenarios have to be written for characters of all types.

As an aside, the scenario makes frequent reference to a campaign setting book, Planes of Power, and I’d recommend a GM get the book before running the scenario in order to get the most out of it.

Overall, Treacherous Waves looks like a pretty solid scenario with an excellent mix of role-playing, skill challenges, and combat. It starts a bit slow (I find that early combat or drama gets players into the game quickly), but should provide an enjoyable experience.

A sandbox-like investigation


Investigations are probably my favorite kind of scenario, so when I saw this one was about to came out I instantly instantly knew I was going to run it. I was not disappointed. When you read the whole thing, you instantly get thrown into the deep end, which is fitting considering the location the scenario takes place at.

As a disclaimer I have to admit that I struggle to give this scenario a good rating or review. Treacherous Waves introduces a bunch of flavorful NPCs and locations, which are all worth visiting as they can all contribute to solving the mystery. I quite like that, because as a result, there's multiple paths the players can take to find out what happened and who is responsible. It allows for a lot of flexibility, something that other investigations typically lack. There's multiple roads to Rome, so to say. I'd even go so far as to say you could also consider it somewhat of an evergreen considering every time you run it, you can find different angles to pursue and get to the same conclusion.

However this flexibility is also the downside. There's a metric ton of information spread out over 15 pages or so that you more or less have to memorize. A GM will to prepare this investigation really well in order to provide the players with the right information at the right time. When I ran it, I provided all the information the PC's asked for, which is roughly half of what is available, yet had some issues locating them.

The information in the scenario is just a bit too much and, possibly, overwhelming for the players. It can also easily have them chase after some red herrings, which again is fitting for this particular location. At the same time my players asked some fairly obvious and logical questions, yet the scenario had no answer ready for them. Compared to other scenarios, and investigations in particular, I had to improvise way more. In hindsight it honestly was too much of a sandbox for an investigation, yet still fun.

I should also comment about the underwater combat and the chase scene. Underwater combat rules can be quite frustrating, so be sure to have a handout ready for those players that are unfamiliar with it. As for the chase scene: some people will hate it, others will love it. I'm leaning towards the latter, but with the side note that it's a bit too sudden. You've never really met the culprit, and all of a sudden you see him and have to chase him. It felt a bit odd and out of the blue, and while fun, I'm not convinced it really added to the overall scenario.

In the end, I did like the scenario. It however is probably a bit too much of a sandbox and can take more time than a time-slot allows. Still, the NPCs and locations are worth it and story-wise it is rather well-written. Even though there are some things that could have been better, I'm inclined to recommend this scenario to others. However due to those issues mentioned above, I struggle to give this scenario more than 3,5 stars. Given the fact that it has a lot of potential to immerse the players in the hands of a well-prepared GM, I'll give it the benefit of the doubt and conclude this review by giving Treacherous Waves 4 stars.


The investigation part of this scenario is great. The chase scene is significantly improved, and some of my players even enjoyed it! The combats are the only(very slight) downside. While combat isn't very important to making this scenario work it shouldn't feel like a foregone conclusion. I think the scenario would have gone exactly the same if I'd just narrated the fights and moved on. That is the only reason this doesn't receive five stars.

5 stars -- fun to play, fun to run.


I had a great time playing this. Note that if you’re the person who arrives to a game and tunes-out the introduction, be forewarned. You’re going to tune-out for a LONG time. This is an investigation scenario. It could be an hour or two before people stop talking and any combat happens.

If you’re a person who takes notes, cares about the NPCs, and talks to everyone… you’re going to have a great time. There are 4 or 5 major NPCs and a handful of side-characters that may or may not have relevance. At a certain point, time will matter, so you have to plan carefully and be willing to sacrifice or at least make tough decisions. In our game, one player was very upset that visiting the market was going to take so much time, and kept trying to argue for less time. In the end, we split up in order to cover more things more quickly, and it hurt us a little, but that was our decision.

To help us out, our GM laid out colored 3" x 5" cards, each with a name of a suspicious NPC. It helped us to track who was who and also to drop extra notes down by each card, as we discovered things. We used it as a sorting system, right on the table.

I see in the other reviews that the final fight is a cakewalk. For us it wasn’t. The real issue for us was:

We had to deal with a flood of water, which slowed movement and eventually halved weapon damage for most types of attacks. Mid-combat, we had to waste time on spells for water-breathing and other non-attack options, just to remain in the fight.

Also, as my own GM note (even though I’ve not read the module, nor run it) I’d like to remind GMs that the surface of water ruins most targeting. It grants improved cover in most cases, which is a +8 to AC, +4 to reflex, and confers the Improved Evasion feat for free (see the Core Rulebook for rules on aquatic environment and cover). So a shark which is fully in the water can easily attack someone partially in the water, but that victim cannot easily retaliate by swinging a blade from the surface into the water – which closely mirrors real life. Magical flames blasting onto the surface of water will not usually penetrate the water, either. A PC must get all the way under and target the shark from under water, and even then you’d need piercing weapons such as an underwater crossbow. Spells are expressly listed as “GM discretion” when cast under water, so you can’t expect everything to work.

EDIT (July 21, 2017): Having now read and run this, I have to point out that my original GM ran this final fight wrong. It was difficult for us because he imagined that the hexagon room that we fight in was walled and when water came up, it just kept building until we were all swimming. This is totally wrong. The hexagon fighting map is docks. There are no railings. You are on wood docks, over water.
When the water comes up, it only goes up to 4' deep over the docks, and only for 1 round. Then it recedes. Basically, the sharks have 1 round to bite, and then they're sucked back into the middle lower area. This is still amazing and fun because the water can possibly bull-rush a PC right off the docks and the gate for the sharks is open. So they can swim out and take a bite while he/she is floundering. However, it shouldn't be as hard as I initially experienced. Nobody should find themselves in a room filling with water. There is no room.

If other GMs are going easy on that stuff, I can see how that would make the final encounter a cakewalk. For me, this was simply a ton of fun, and well balanced for a "normal" party. I intend to buy the module, and run it myself.

The best investigative scenario I've played or run in Pathfinder so far


It has its problems, don't get me wrong. From the GM side of the screen, I can say that it's finally time (in my opinion, at least) to move all of the stat blocks to the appendix. Flipping between 3 or 4 pages for stats with the map on another, separate page is just brutal. It's got a chase scene in it, and it's a weird one of a kind I don't like. It doesn't come with necessary handouts and the chronology is too scattered--I made a cheat sheet and uploaded it to shared prep but it's really the kind of thing a scenario like this should come with. You almost cannot run it without having something like that available because the chronology isn't broken down into a list somewhere.

But the investigation works really well. All the clues came together perfectly for the party. Had the party's GM remembered to give them one more hint, they probably would have figured out the one part they missed, even. Everything just... worked. That's not normal. I was amazed.

So... it gets five stars from me. In my opinion, once you do the prep it's the best investigative adventure in Pathfinder right now, at least out of the ones I've played. Would more than happily GM again.

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Community & Digital Content Director

Announced for April release!


Oh man, I'll have to choose between my undine pirate and my Silver Crusade paladin for this one!

Looks like a great scenario.

Sovereign Court

So i get to terrorize PCs with water combat rules right? :D

Paizo Employee Pathfinder Society Lead Developer

Imhrail wrote:
So i get to terrorize PCs with water combat rules right? :D

Come on in; the water's fine—minor spoilers for #8–19 and #8–20:

This adventure involves a fairly modest amount of underwater combat, and largely if very bad circumstances befall the PCs. #8–20 involves far more underwater combat. You might enjoy picking up Pathfinder Campaign Setting: Aquatic Adventures the following month!

Paizo Employee Developer

I don't know who did the art for the workshop, but the submersibles in it are truly wonderful.

Paizo Employee Pathfinder Society Lead Developer

Ferricstate wrote:
I don't know who did the art for the workshop, but the submersibles in it are truly wonderful.

That would be Sean Macdonald, who illustrates many of the custom maps in Pathfinder Society adventures. In fact, he asked about those submersibles specifically during production to make sure he depicted them just right.

If you ever have questions about who created the art featured in an adventure, be sure to check out the credits page. There are a lot of excellent artists working on Paizo products, and it's great to recognize them for their contributions.

1 person marked this as a favorite.

Ok, maybe i am dumb, but where in the scenario is the "contributes directly to the ongoing storyline of the Silver Crusade faction." part.

Grand Lodge

What maps does this use? I'll be running it for a convention next month. Figured I'd order any I don't already have.

Paizo Employee Developer

kevin_video wrote:
What maps does this use? I'll be running it for a convention next month. Figured I'd order any I don't already have.

The Gamemastery Flip-Map: Warehouse and the Pathfinder Flip-Map: Elemental Planes, as well as two new maps included with the adventure.

Sovereign Court

1 person marked this as a favorite.
GreyYeti wrote:

Ok, maybe i am dumb, but where in the scenario is the "contributes directly to the ongoing storyline of the Silver Crusade faction." part.

Same question here.

Dark Archive

GreyYeti wrote:

Ok, maybe i am dumb, but where in the scenario is the "contributes directly to the ongoing storyline of the Silver Crusade faction." part.

My guess is the expeditions goal will be further flushed out for a silver crusade nod in a future scenario.

Grand Lodge

Having read this, I have to admit that I'm slightly surprised that there's no "check box A, B, C, and D" options at the end.

Sovereign Court RPG Superstar 2009 Top 32

I've read that this advances the Silver Crusade plotline... but how exactly? I haven't noticed the Crusade in this scenario.

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