[...]1. Play Intrigue Card: By assigning an Agent to one of the actionI believe that's the quote you're looking for.
spaces on Waterdeep Harbor, you play a single Intrigue card from
your hand. If you have no Intrigue cards, you cannot assign an
Agent to Waterdeep Harbor.
When you play an Intrigue card, you follow its instructions
immediately. Its effect takes place just once. For example,
Lack of Faith forces each opponent to remove 1 Cleric ( hH )
from his or her Tavern if possible. If an opponent has more than
1 Cleric, you cannot force that player to remove additional Clerics
with this card.