Cthulhu Invictus Companion is a collection of three scenarios for Call of Cthulhu, pitting investigators against cults from different regions of the ancient Roman Empire.
- Those with the will to survive being dragged through time and space can learn to harness imponderable power to their own needs provided they offer the appropriate sacrifice to The Opener of Ways.
- The Akeru have long lived in seclusion at the base of Mount Serbal, protecting the world from a horror that would destroy humanity if ever released.
- Initiates who wish to join the Teutates must first survive a grueling journey to the Severn Valley and then undergo a ritual that leaves them undead.