Experience fantascience roleplaying at the end of time. Escape the end of history. The eternal civilization is perfect. So say the gods, the machines. Will you defy the endless circle of awakening and forgetting? Can you kick a hole through the sky?

When the anomaly appeared at the Earth's core, the Substratum Protocol was initiated. You are the best and brightest scientists we have left, our last hope to stem the apocalypse. You are the Substratum Expedition Team. Descend. Learn. Survive.

A full-length adventure for Heart: The City Beneath RPG, written by Gareth Hanrahan and illustrated by Sar Cousins.

This new expansion to Sentinels of the Multiverse explores the heroes, villains, and environments of the Multiverse — those who travel through it, those who have been touched by its vast impossibilities, and those who would seek to destroy it!