It isn't unusual for Fern to be in the catacombs, doing typical Hunter business. It's a good place to find monsters trying to sneak a meal out of Trenchies, and even though it isn't the cleanest place it reminds him of the dungeons back in Ooo. That gives it a nostalgic edge, so he doesn't mind.

He isn't expecting to find a note down there, shoved in between two bricks just over his head. He very nearly misses it but Blodeuwedd, perched on top of his hat, catches it and grabs it with her forelegs with a chirp. Confused, he takes it from her and reads it, his brows knitting together in bewilderment. It seems like something out of an old book rather than some discarded note, so he pockets it for safekeeping.