When Darkness Comes: The Nameless Mist (2005)

From the publisher:
This expansion has been eons in the making... Arkham is a strange place and when you dorm at Miskatonic U. it only gets weirder. Explore the darker side of college life. But, be sure to take notes... there will be a quiz!

This When Darkness Comes expansion features new rules, six new scenarios and one GM run, multi-part campaign. All scenarios are set on the beautiful campus of Miskatonic University in the lovely town of Arkham, Mass. and feature creatures and themes inspired by the Lovecraftian mythos.