This short fifteen room dungeon crawl written by Peter Spahn is designed for a smallish party (5 or so player characters) of experience levels 1-3. Normally, these low-level adventures are designed to hand-hold players new to RPGs. That does not describe this adventure. Spahn clearly feels that there is plenty of fun in to be had at these novice levels for experienced players and so do I.
The non-spoilerific adventure background is simply that a sage named Atarin is investigating subterranean ruins in a small town and has been getting veiled threats implying that his attentions are unwelcomed. The PCs are part of an Adventure Guild that sends them to assist Atarin. When the PCs arrive, the Atarin expedition has not been heard from in several days. An alternate adventure hook is suggested that the PCs merely stumble upon the abandoned campsite, which seems more mysterious and evocative to me.
Delve comprises many classic RPG tropes: a depraved cult; a hapless sage that awakens an ancient evil; a xenophobic alien species that just wants to be left alone. The heavies of this adventure are the Caltha, an amphibious intelligent species that, though in decline, can still cause trouble to those that interfere with them. I would love to see the Caltha appear in a higher-level adventure. Spahn gives just enough details about them to arouse the imagination, not unlike the Kuo-toa of Gygax or the Deep Ones of Lovecraft.
The meat of the adventure comes from the conflict inherent in the three well-detailed groups interacting in this adventure. Not only has Atarin's expedition angered some local humans, he has loosed a group of grumpy fishmen. The opportunities for role-play abound here.
The random encounters here are more detailed and varied than is typical in the classic TSR modules. Ten encounters are detailed with a setup that provides the game master with a sensible context for the events. Spahn has also been careful to refer to existing LL rules (like those covering blindness and opening doors) rather than recreate them. In one notable place, he relies on an ability check to provide the PCs with more plot information. I am a big fan of ability checks and wish that the classic run of TSR modules had used them more.
The production of this short adventure excellent. Great maps by Dyson Logos, a consistent layout and tight prose make this content easily digestible. All told, this product provides excellent value for the consumer and a yard stick for other publishers.