This is the third 4th Edition adventure from Open Design - the first two were Wrath of the River King and Halls of the Mountain King - and is probably my favourite. Like Wrath, this adventure has the fey centre stage but the tone here is much darker as the shadow fey (or scathesidhe) replace the eladrin that dominated the previous module. Shadow demons and demonic cockroaches rub shoulders with black-hearted fey, eye golems and even stranger beings.
This isn't really like other D&D adventures - the action begins in the city of Zobeck before heading down the Shadow Road and into the Shadow Realm where the Courts of the Shadow Fey are waiting to be discovered by the PCs behind veils of illusion. Once they've done so, the sandbox nature of the adventure can span several months of game time as the PCs get involved in political intrigue, seduce courtesans, hunt magical birds and duel arrogant noble fey in order to advance in status and gain audiences with the Queen of Night and Magic and the Moonlit King.
This adventure has 100 pages of densely-packed text, cool art and great maps. Highly recommended.
[5 of 5 Stars!]