As you approach the box, the man get's even more disturbed. It becomes quite obvious that he's sweating furiously at the moment and is still unsure of your own intentions. He then glances farther back into the cavern, and then down on the ground towards what appears to be a pit full of ash and burned wood, quite possibly a fire pit.
As you approach the box, you can make out that it looks to be a tool-case of some kind, made of bronze. It has a small latch on the front that appears to be locked, but it would take no skill to unlock the device.