This adventure focuses on a Zhentarim attempt to spread terror in Mistledale, although it is suitable for almost any lightly settled area northwest of the Sea of Fallen Stars. "The Raiders of Galath's Roost" is suitable for four 1st-level characters, but PCs should be at least 2nd level before tackling the adventure's second half, the Zhentarim Citadel. Even in the first half of the adventure, many of the encounters are quite formidable for 1st-level characters, and the PCs might find it necessary to withdraw and recover one or more times before completely exploring the ruins.