quote Lost Odyessy FanSite

Now, you can access a "secret" warehouse here (heh not really). See the narrow path those 2 guards guarding at the north west section of this area ? Yes, there's a way to pass through the guards here. First you need to talk to both of the guards. After you talk to them, they'll start moving back and forth from their initial position. Now, use this chance to sneak through FROM THE SOUTH (not the north one). After a bit of tries, you'll make it. You need to watch out from both guards, and quickly push the crate blocking the way from the south and head down the ladders quick. It might takes several tries, i managed to get in after about 10 minutes.

Building Warehouse

Inside, check the pots for items, and one of the guy here sell items/weapons. Go purchase Lightweight Saber off him, one for Kaim and one for Seth, and dont forget to buy Aqua magic. Dont bother buying weapon for Jansen, he's better off using spells. To exit, just take the south door and you'll be back in the resting room. Push the crates to make your way, and exit the area.