The Destruction of the Altar

Chapter XVIII

Agia, twin sister of Agilus, agrees to help Severian prepare for the duel, but then she involves them in a cab race. Their cab plows into a giant tent, destroying the alter of the Pelerines and thereby losing the Claw of the Conciliator, a holy gem.

Hypogeon - a cthonian name, perhaps an aspect of the Increate.

thyacine - a wild animal that apparently roams the streets of Nessus. It is a misspelling of "thylacine," the Tasmanian wolf.

palatinate - the territory or district under the rule or jurisdiction of a palatine or count-palatine, a lord having sovereign power over a province.