Historical Rules · 10 August 2018
Rule 719.5d
Official source text from the 10 August 2018 Rules release
At the end of a subgame of an Archenemy game, any face-up scheme cards in the subgame command zone are turned face down and put on the bottom of their owner’s scheme deck. Then the archenemy moves their scheme deck from the subgame command zone to the main-game command zone and shuffles it.