You do not need to fulfill the To Close requirement. Search the location for additional villains:
• If you don’t find any villains, the location’s When Closed effect happens: First, apply any effects that say “before closing.” Then banish all of the cards from the location; it is now closed. Finally, apply any effects that say “on closing” and put the location card back into the vault. The location is no longer in play, and all characters that were at that location always immediately move. After the encounter, the exploring character may no longer explore.
• If you find any villains, the location is not closed. Banish any cards in the location except any remaining villains and shuffle the deck; if all distant locations are guarded, banish the villain you encountered.