[Have an eyebrow raise at the words, but fortunately that's as much of a reaction as they get out of him. He really shouldn't be telling you more about those Corridors, but he doesn't think he'll just be able drop or change the subject. As long as the boy doesn't go asking about it to people on the island, there is likely little enough harm in explaining it.]

Corridor of Darkness, it's a method of traveling through the Darkness to get from point A, in this case, the castle; to point B, here to your residence. Or any other location within these known worlds.

[And here's to hoping you actually pull this off successfully as he goes into further detail for your benefit.]

Just don't forget to put the coat on before you open one up... if you do it right, it should bring you here.