From introduction:
Tenants Of Hell is a Cthulhu Rising adventure designed for a group of experienced player characters (PCs) who are members of the Interstellar Colonial Marines. It was written as a follow-on from [SM04 The Abaddon Key], but with a little modification, a Keeper can run it as a stand alone adventure or insert it into another campaign.
Set against the backdrop of a planet-wide war, the adventure is concerned with the discovery and subsequent race by several factions to acquire an apparently derelict and ancient alien starship built by that most ancient and enigmatic of alien races, the Elder Things.
The PCs will become involved with one of these factions when they are approached and offered what initially looks like a chance to make some easy money out of the war. Events will soon escalate out of control, leading the PCs on a journey to the brink of sanity itself.