Browsing through season 10 scenarios, I realized I had not rated this little gem. Seeing only 1 review, I thought I should add my perspectives on this adventure.
Reading Cyrad's review below, however, I must surrender the field. They have succinctly and accurately summarized my experience as a GM. I experienced no particular difficulties in preparation of the scenario. The Social portion proceeded surprisingly smoothly (mechanically). The subsequent trek was enjoyed by all, I think.
I confess I did not encounter issues 1 or 2 that he noted, but I understand and agree with issue 3. That said, my party didn't notice/comment... they were distracted with other concerns! :)
I unreservedly recommend this scenario, to play or to GM.
I bought this book for the Ex-Paladin Archtype. Upon reading it, I rolled an Ex-Cleric! Solid player book, review below more eloquently and fulsomely addresses its contents. For me: I am confident it was a good purchase.
Reviews below thoroughly detail the 'problem' parts of To Seal the Shadow. I had the pleasure of playing this scenario online (R20) earlier this week in a pickup PFS game. I had fun. My friend also had fun. I think this module is stronger than the 2.5 star rating average at time of positing. So I thought I'd write a review.
The scenario plot was straightforward; don't go in expecting an investigation/intrigue focused scenario. I nonetheless enjoyed the progression of events: there were things for every character to do, and little twists to encourage interesting tactics and roleplay.
I particularly liked that the scenario had easily accessible background elements. To Seal the Shadow features a neat little locale with plenty of low-key opportunities for interaction with the locals. All players seemed to enjoy getting 'in character' at various points throughout the adventure, picking up on flavour 'hooks' in ways that complemented the objectives we were trying to accomplish. Unlike some scenarios which lock history, backstory, and flavor away behind high DC background skill checks or specific questions that the party doesn't think to ask, this one seemed to deliver story/background to the players well.
Picture this: it is a weekday evening. You want to play PFS. You want to play something linear with a fun and straightforward plot that can wrap in 4-5 hours. You want some flavour/background and low-key RP alongside your combats (not merely as a prelude to the dungeon entrance). To Seal the Shadow could be the scenario for you!
...if you have a DM that has visited PFS prep to get the player handouts, delivers a copy to each player at the start of the scenario, and moves the verbal duel along at a decent pace.
My 2 ep on the dreaded verbal duel. During scenario marshalling, our GM gave us each the handouts and instructed us to assign tactics to skills in advance. Then, at the start of the encounter, our GM was clear what our team's objective was. Time Taken > Narrative/Plot/RP advancement, but our GM was prepared and each player had a nifty little RP segment or two. It was 'okay'.
Having now used the mechanics in play, I 'see' better how UI's rules might work in a 'normal' game. So, objective accomplished for Paizo I guess?