This adventure is 29 pages long, 1 page editorial, 1 page editorial/ToC, 1 page SRD, leaving 26 pages of content, so let's check this out!
This being an adventure-review, the following contains SPOILERS. Potential players may wish to jump to the conclusion.
All right, still here? When the PCs arrive at the harbor-town of Tawwa, it is a bureaucratic nightmare par excellence - the last couple of days have seen a series of grisly murders of bureaucrats, officials and members of prominent families have been murdered and the PCs are promptly recruited to take a look at the scenes of the crime. Now the investigation is rudimentary - very rudimentary. Essentially, there is one generic clue that doesn't help the PCs to be found and the build-up of any sense of mystery is immediately squashed by an assassination attempt on the mayor and his mistress, which the PCs witness and hopefully thwart, the culprits being Garuda. While magic and the clues it can deliver has been taken into account, the mystery is essentially none - the PC's investigation has no bearing whatsoever on the plot and does not contribute anything to the overall story. After vanquishing the outsiders (taking hostages being not accounted for), the PCs will have another thing up their hands - the harbormaster has been brutally slain while the PCs were busy saving the mayor.
Again, though, there's not much for the players to find apart from a hidden dock and a ship that supposedly sank, hinting at a mystery that would be interesting - would it not be explained away easily whether or not the PCs succeed at even the most basic of investigations. Turns out that the changed MO of the last killing points towards another culprit: Aboard the ship once was a creature called Aurspeily, which broke through the bars when the harbormaster and his associated tried to steal the box. The creature has broken through the floor, thus forcing the PCs to follow it down into the city's sewer. The sewers get some neat maps, but the harbormaster's warehouse is not covered, which is problematic since honestly, I had a hard time picturing how the place was supposed to look. Worse, once in the sewers, the PCs will encounter a Garuda hunting party that essentially serves as captain exposition, invalidating any research the PCs may have done. Everything up until now has been an utter waste of time. Yeah. The story goes as follows: The city is covertly run by a Naga which the Garuda hunt. The dead people were servants of the Naga and the supposedly sunken boat was chartered by them before the Naga's servants tried to lose it in the bureaucracy/etc.. If they have the Garuda with them (who actually ASK for parley), they may even take the Aurspeily in and calm the beast. After encountering some Naga cultists and a mad invisible stalker (who would have made a great red herring in the investigation), the PCs find the Naga's hideout, a spiral-shaped gauntlet of deadly traps -after braving several admittedly smart traps, the PCs will square off versus the Naga for an urn stolen from the Garuda which contains the ashes of one of their champions as well as the safety of the city. The spiral-shaped lair is also lavishly illustrated.
Editing and formatting are good, though not perfect - I noticed e.g. minor typos, two tense errors etc. Layout adheres to AaW's 2-column standard and the pdf comes in 2 versions, one optimized for printer-use. As per the writing of this review, the herolab-files have not yet been added, but will be. The pdf comes with full bookmarks and player-friendly versions of the maps, which is neat.
This module by Michael McCarthy is a disappointment to say the least - clocking in at only 14 pages sans the statblocks, the low page-count essentially wrecks what could have easily become a stellar module: All the pieces are there: A mysterious series of murders, a conspiracy, interlopers to the established city, an interesting finale. The problem is that this module is under the delusion of being an investigation when it isn't one. The investigative scenes provide no option to unearth any clues regarding the nature of the culprits, the conspiracy or the background of the adventure - all of that is relegated to one narrative deadly sin of emptying the exposition dump on the PC's heads. Worse, the investigative scenes not only remain utterly bereft of consequences, not even the most basic of PC steps apart from 2 high-level spells (NICE!) are covered -there is no information to be gleaned from any NPC or any amount of investigation and the whole act is essentially a barely disguised exposition dump to railroad the PCs into a confrontation with an assassination attempt - one that does not take into account the taking of prisoners, mind you. The investigation-areas also lack maps, which is especially a pity when the second area is concerned, where the PCs get to know about the second potential killer introduced to the city. Again, though, investigation is utterly futile and bereft of any meaning whatsoever. Worse, the revelation that could point towards the unearthing of the conspiracy is also utterly invalidated by an impossibility of the PCs finding out about the significance of any of their findings. To add insult to narrative injury, the supposed chaos that besieges the city is nothing short of a note in the background - nowhere does investigation or narrative ever mention this again or see any true repercussions, making the set-up feel completely superfluous.
And then there's the moral ambiguity - turn out the killers actually are good-aligned creatures that brought a potentially lethal thing into town and want to root out a mastermind of a conspiracy. Well, if said foe is vanquished, wouldn't the city descend into anarchy? Are their murderous actions justified due to their victims being cultists/adherents of the conspiracy? There is potential here and nothing is realized.
This module is an exercise in utterly wasted potential: Where "It all falls down", also by Michael McCarthy, is a fast-paced action romp, this module tries to use a similar formula, but fails in all the ways in which the former succeeds. Where the investigation in B3 was short and rudimentary and there to present a simple background story and get them into the action, this module presumes a complex narrative and at the same time provides no way for the PCs to unearth any component of it. The railroadiness and exposition dumps make this module fail as hard as humanly possible on a narrative level and utterly destroy what is essentially an awesome set-up. The ultimate problem of "To Catch a Serpent" is page-count: The set-up per se is awesome and could have been developed easily into a stellar module by adding A LOT of information - on the city's rising ambience of fear. By adding NPCs to interview, clues to find, actual investigations that help and give the PCs an edge versus their opponents. By developing the moral conundrums between the factions and perhaps include actual responses of the factions to the PC's meddling à la assassins, summoned monster attacks etc.. There also is a distinct lack of gravitas for any action that happens in the module - whether by PCs or NPCs and even the mad being that is essentially a glorious red herring that, via e.g. city records, could have made for a great DM-twist, is nothing more than a glorified random encounter. Not even the interesting villain's lair in the end can make up for the fact that this module essentially tries to jack-hammer a complex investigation into an encounter-formula that is simply not up to the task and relegates the players to the role of impotent watchers of the things that unfold.
And page-count is no excuse per se: 0onegames' The Sinking-series features a couple of compelling investigations in less pages, but the modules don't try to jam too many story-threads into the content. Depending on your perspective, this module tries either too much at once for the page-count and fails to properly develop all of the ideas or it tries to tell a complex story and omits too much and just fails due to its shortness. Either way, the module, as written, fails - horribly. In fact, bas enough to make me go one star - only that the module does not deserve it. A talented GM can easily take the story-threads, develop 12 murder victims, add clues, flesh out the city, develop the ideas etc. and create a web of clues and make this an awesome piece. But the amount of work this would take is extraordinary and since I can't rate this module for its potential, but rather for what's there, I'll settle for a final verdict of 1.5 stars, rounded up to 2 due to the potential of its set-up. Unless you're unwilling to devote a lot of time to fleshing this module out steer clear - in order to be more than a ridiculously passive railroad, this module needs essentially a complete overhaul.