With the end of the first boss fight, the door was finally opened. The three raiders quickly went out of the room, leaving all the enlightened torches and the buffalo's corpse behind.
The door they used to get out was carved and made exactly identical to the door they used to get in as if the two can be used as both entrance and exit. Then as soon as they arrived outside the room, they spot some kind of circle within the reach of light, with flickering firefly wanders above them painted by the shade of fresh blue.
“What’s that?” With a face full of wonder, Staas pointed at the circle.