It's Always Swordfish

It's Always Swordfish

As you're farting around on the Poop Deck (huh huh) a wary-looking pirate rushes up to you and grabs you by the shoulders.

"Avast," he growls. "What be the password?"

"No," you reply, "'swordfish' be the password."

"Aye. That it be." he replies, and winks at you as he unlocks a padlock on a trap door leading deeper into the ship.

Notes

Unlocks Belowdecks.
Does not occur unless you have read the relevant section of your father's MacGuffin diary.

The use of "swordfish" as a password may be a reference to either the 2001 movie Swordfish, or to a scene in the much-older Marx Brothers movie Horse Feathers that inspired the newer movie's title.
"Swordfish" is a reference to the book Night Watch, by Terry Pratchett. After Vimes discovers that a secret group is using swordfish as a password, he thinks, "Swordfish? Every password was swordfish! Whenever anyone tried to think of a word that no one would ever guess, they always chose swordfish. It was just one of those strange quirks of the human mind."
The '"What be the password?" "No," you reply, "'swordfish' be the password."' is a possible reference to the Abbot and Costello "Who's on First?" routine, in which the two banter on various positions in baseball, as well as the names of the players who are on said positions. One of the lines from the routine is "Who's on first, What's on second, I Don't Know's on third."
One of the passwords in the Impossible Mission game from the 1980s was "swordfish".
For more swordfish-as-password references, see this Wikipedia page.