Anlo moves to the door at the far end of the room. Khali remains at the top of the stairs in a position to cover him. When he opens the door, Anlo sees the astonishing sight of a fiery portal set into what normally would be a wooden wall in the food storage room under the tower. With the door open, Khali sees the orange glow intensify and cast a fiery light into the cell/storage room.
Through the portal Anlo sees a vast open hall of cold grey stone. Some sort of labyrinth is carved into its floor. And the hin stands at the top of long stairway. He apparently is able to see through the portal too, because when he notices Anlo at the storage room door he darts the remainder of the way up the stairs, throws on his cloak's hood, and vanishes.
Anlo then realizes the portal is gradually closing up. The flaming circle is slowly shrinking and revealing the ordinary wall behind. At the rate is is closing there is probably a minute or so before the portal would be gone.