I cannot express with the English language how glad I am to be done with the Horned Hold.
But before we move on, let's take a look at another Side Trek from Dungeon #156. This one's called the Cisterns, and takes players to an out-of-the-way shrine to Torog, god of the Underdark.
Like much of the optional content of Thunderspire, the Cisterns has a pretty excellent backstory. It draws on Vadriar, one of the characters featured in Thunderspire's description of the Seven-Pillared Hall.
Vadriar is a human sage who has recently stumbled upon a secret trogolodyte temple located near the waterways beneath the Hall. He's discovered that the trogolodytes are planning to collapse the upper levels of the Labyrinth as a tribute to their god Torog (killing everyone within), but upon being detected by the trogs he's become the victim of an evil curse that prevents him from telling anybody what he's discovered or leaving the mountain.
As a result, players are going to find Vadriar as a trembling wreck, absolutely terrified of the apocalypse he knows is coming but powerless to do anything to prevent it. He is, though, able to point players towards a vague threat in the general vicinity of the Cisterns and hope that they're able to join the dots and save the Labyrinth.
The encounter itself doesn't intially seem as good as the set-up. Neither the Trog Maulers nor their pet Grick (a kind of subterranean snake-worm) are very exciting - they're just your basic bruisers. Instead, the encounter relies on a Trogolodyte Curse Chanter to provide flavour and character to the fight, and dual-level terrain to provide mechanical interest.
The players start on an upper level, with the Maulers and the Grick. The lower level has the Chanter, along with yet another instance of the cliched defence-boosting magic circle. There's a 20 foot drop separating the upper level from the lower, which can be safely traversed using a conveniently located slippery slide. In short, the players can get down easily, but getting back up is tougher.
The cleverness here is that the encounter reverses expectations. Up until this point, players have been taught to get into melee with casters as soon as possible and dispatch the hired help once the brains of the operation are squashed. The caster, however, turns out to be entirely un-worried by meele - between its aura and the circle it has a staggering effective AC of 26 - and players who head straight to the lower level will find themselves bombarded by the Maulers' javelin attacks as they struggle to escape the Curse Chanter and return to higher ground. In short, the Chanter is bait in a cleverly executed trap.
In the event players engage both levels simultaneously, the Chanter is able to teleport his allies to his side, where they can all gain the defensive bonus of the circle - not ideal, from the Trogolodytes' perspective, but a strong answer to divide-and-conquer tactics from the players.
I really like this encounter. It does a lot with only a handful of enemies and a very small map. Much like the Tower of Sunset, it's a nice change of pace from the main module content and, provided you can find room in your XP budget for it, it's well worth running.