Final Fantasy xii PS2

[frustrated01]

In Final Fantasy xii after you defeat the ghost in the waterway and the kid opens the door to the empty house you get a dusty letter. Then you go back to him some time later and he tells you he thinks it has something to do with the waterway gates but you have to have a key and he seen a moogle running aound saying something about the key. You talk to this one guy and he says a moogle trip over him and the moogle dropped his sweets and something else.. Well how do you get the key to elplore the rest of the waterway? Am I supposed to give the moogle at the westgate who is upset something and he tell me how or what?