The 5th adventure is The Dragon of Najkir, for 6th level characters. A bronze dragon is denning beneath a remote island monastery. An evil assassin who is the son of the dragon's noble former companion retreats to the monastery to avoid punishment for his crimes. Out of loyalty to the assassin's deceased mother, and ignorant of the assassin's crimes, the dragon starts attacking ships that approach the monastery in order to protect the son from capture. The adventurers are sent to the monastery to rescue survivors of a ship wrecked by the dragon, who are sheltering with the monks.
Everything that is present in this adventure works, but the piece feels like either it needed some more time in development to enhance the content, or else it originally did have more content but things were cut or simplified, perhaps for space reasons. The result is a promising setting that feels strangely under-written, and a quest that I suspect would take most groups less than one four-hour session to resolve.
The Good
The art for this one is absolutely gorgeous and reflects the best examples of the traditional painterly 5E style (think the better pieces in Curse of Strahd or Rime of the Frostmaiden). I love the goats, and I wonder if they are a nod to the inside joke among Frostmaiden designers.
Two great full-color maps of the monastery and its demesnes. Even DMs who totally disregard the adventure as written, or heavily re-design it, will be happy to have two really nice, keyed, full-color, 5' scale expansive location maps that would work well as locations in many campaigns.
What story there is tracks pretty logically and everyone's motives make sense.
Even if I don't think the adventure takes full advantage of it, the physical location is an interesting one and DMs might get more use out of it beyond what's provided here.
Complaints
The visual centerpiece of the adventure is a two-level monastery map with 39 keyed locations. The bulk of its text describes these 39 locations. Unless the party is full of players who just really like to snoop around inside friendly areas and steal from allied NPCs , the structure and hooks of the adventure mean that most groups will visit less than 10 of these spaces. Some of those 10 or so areas contain traps, but most of those traps are known and controlled by friendly monks who have every reason to just tell the players how to avoid or disarm them.
The assassin, and his secret invisible sexy oni ally, and his two bodyguards (who are secretly dopplegangers, but as written this isn't relevant) are intriguing but apart from the assassin/dragon relationship there's nothing much going on with them. With the oni, in particular, it feels like something got left on the cutting room floor.
The main challenge of the adventure is in convincing the dragon of the assassin's guilt. The way the adventure suggests this is best accomplished is depressingly unimaginative: beat the assassin down to 20 hit points or less, whereupon he will surrender and confess everything to anyone, including the dragon if brought face to face with him. Since all the monks and all the shipwreck survivors know exactly who the assassin really is by the time the players arrive, no real investigation is required. It's pretty much just, "Thank God you're here; please go beat that guy up." And beating that guy up is empirically the right thing to do here.
There is a better adventure available here with a bit of re-working and additional development. Too many friendly NPCs who are sure exactly what's going on are alive and in control of the site when the players arrive. The whole thing would probably work better if the players arrived in a situation more like The Thing, or Let the Right One In, or the climax of Scream. I think it would work better if the shipwreck survivors arrived, blew the assassin's cover, and he and his buddies started killing everyone. The fact that you've got dopplegangers and an oni means monks and survivors could have been replaced and impersonated before the players arrived, but in enough haste that environmental storytelling, evidence, hastily interred bodies, journal entries, and investigation could ferret out the truth. There is also certainly enough physical space available in the monastery to include more story - and additional stories. It could be pretty thrilling. As written, it probably isn't.
One more thing. The adventure starts with a dragon attacking the ship on which the players are sailing to the island, either damaging or sinking it. I worry a little about this, not because it's a bad idea, but because it's the sort of encounter that D&D's rules tend not to handle very well. Whenever I see an encounter that tells me to look up such-and-such ship map and stats in the DMs' Guide, I always have the sense of an adventure designer just kinda throwing up their hands as to how this encounter is going to technically work.
Verdict
I'm torn. Nothing in this one is bad. I just feel like it's a great adventure site and offers the potential for a great adventure - and might even inspire DMs to shape it into one. But, on, paper, what is actually there is not a great adventure; it's only fine. B-.