From publisher blurb:
Float down the sewer river of the dreamlands with Through Ultan’s Door double issue 3. This issue presents a pointcrawl along a sewer river of the dreamlands that connects the dungeons from issues 1 & 2 with 7 new locations. It introduces an entire settlement, the Sanitarium of the Benefactors, and numerous factions including the sewer wyrm Cephaia, Prophetess of the Muddled Waters; her rival the Cranemay, melancholy fey witch; and the Lurid Toads, ominously polite cannibalistic parasites. Complete with a giant dreamy sewer encounter table, and rules for playing your very own opium dreaming wizard! It is illustrated more lushly than ever, with over 30 gorgeous illustrations by Huargo, Orphicss, Gus, Daria Khlebnikova, Johan Tieldow, Jeremy Duncan, and David Hoskins.
It is written for characters of 1-4 level in Advanced Labyrinth Lord but is easily usable with any older edition of D&D or their retro-clones.