According to legends, this is it: the dungeon wherein lies the mystical Amulet of Zot. Whoever manages to retrieve it will gain great power and glory. Only... it probably won't be you.
You begin Succession as a rogue adventurer: a smart but perhaps unwise fellow celebrating your recent victory over a dire rat by seeking the Amulet of Zot. You will probably die. And that's where your adventure begins.
When you are killed by one of the dungeon's many occupants, you start back at the beginning with one minor change: you now control the monster who killed your previous adventurer. Should you die again, you will return as the monster who killed that monster, and so on. Someday, you'll die to something that's strong enough to claim the Amulet.