The game has a set of Story cards which are numbered, and which can be triggered by other cards telling the player to locate a Story card with a specific number. This can potentially lead to another Story card being fetched, and so on, until the Story is resolved. There may be conditions connected with the advancement of a Story, and if the conditions are not met, the Story can end without being resolved.
Stories can be initated by Sea Event cards, Expedition cards and Denizen cards; those cards may trigger some Skill Test or choice, whose outcome text includes a number surrounded by pluses (like "+13+"). In such cases, locate the correspondingly numbered Story card from the Story deck, and place it under the Ongoing Story cover card without resolving it, and place the card that instructed you to fetch the new Story card in the Story area of the Ship Board for the player who caused the event to happen (usually the player whose turn it is).
The newly fetched story card will stay under the Ongoing Story cover card until an End of Act puts it back into play.
Ongoing Story
Ongoing Stories are cards that have been fetched from the Story deck according to the instructions of another card (typically the outcome of a TEST or CHOICE). When they are fetched, they are placed below the cover card for Ongoing Stories, while the card that triggered fetching the Story card is placed in the Story slot of the Ship Board of the player whose turn it is. (This is later used to track who the next step of the Story belongs to.)
At the End of an Act, each card below the Ongoing Stories cover card is moved onto the card deck of the same card type (meaning having the same back, and placed perpendicular (turned sideways) there, so remind players that the card is part of an Ongoing Story. The card types are Sea Event Card, Expedition Card and Denizen Card. The next time a card is drawn from that stack, if it's drawn on the Turn of the player who has a matching card in the Story slot of their Ship Board, the Ongoing Story card is resolved immediately. Otherwise, it's placed face down in the Story slot of that player's Ship Board, and resolved the next time that player would draw a card from the same deck.