The secret passage of Yu Song Castle is about 1.5 kilometers long, with most parts being so narrow that only one person can pass through. In slightly wider sections, there are three venomous spiders the size of humans. Wizards often do such things, raising servant beasts to serve as guards. Barbara placed them here, evidently to please Duke Golan-Elsen. However, these creatures might scare ordinary people, but to Brand, they were just a total of 9 points of experience.
The other end of the passage leads to a row of wine racks in the cellar of Yu Song Castle. Since it's meant to be an escape route, it wasn't completely sealed. Brand found the mechanism on the wall that moved the wine rack, which was mounted on iron rails, to the side with a little searching.
