With no more Deep Ones incoming, they turned toward the mural when Hassan yelled, "Stop, there is a trap!" He lightly jumped from the doorway over to the wall beside the mural. He moved his foot out into the area in front of the mural, and holes opened waist-high in the wall below the mural. 30 or 40 silver bolts started shooting from the wall, bouncing off the far wall and clattering to the stairs below. He moved his foot again through the area, and 10-12 more bolts popped out at a much lower velocity. One hit the railing and skittered to the group's feet. Intevar picked up the bolt and studied it. He hefted it in his hand to feel the weight, saying, "Unless I miss my guess, this is mithril, a king's ransom worth in all these bolts. Sounding suddenly somber, Arya quipped, "Worthless unless we survive to spend it; let's see this mural."
Before being set in motion, the mural depicted a slightly larger-than-life humanoid being standing in front of a large group of primitive-looking creatures. They had tusks protruding from their mouths and were dressed in ragged skins. Tormund said, "Those look like trolls and ogres. No one's seen them in thousands of years, but they are depicted here and there."
Once mana was applied to the disk, the scene moved forward. The humanoid raised its hands and cast or spread something over the whole group; the trolls began transforming into something new. "Giants," Tormund said. The scenes moved forward to other huminoids in different places transforming other creatures—gibbon-like arboreal creatures into what looked like Children of the Forest, fish-like creatures into Deep Ones, trees into Weirwoods, deer into green men. On and on the scenes went, depicting seven different large humanoids changing many things by transformation. Siora said, "It's as if they were evolving the creatures they found and almost like they were instilling magic in them too. To make them in their own image?" Brienne said, "I saw nothing that looked like men?" Intevar added, "But we saw all the lines of craft flights going all over the world; perhaps men and all the differing kin were evolved elsewhere?" A numb, disordered understanding settled over the group, and Arya snapped them out of it, demanding that they keep moving forward.
Down the stairs they went with Hassan in the lead, looking for traps. At the bottom of the stairs, Tormund began gathering the bolts that lay on the steps, and Hassan shouted to stop going down. He turned to Siora and asked for her staff. Hassan lay prone on the stairs and waved the staff near the bottom steps. Once again, holes opened and bolts shot from them. One bolt came so close as to cut his clothing. Three times he waved the staff, and on the fourth no more bolts came out. Tormund continued gathering bolts and putting them in his pack, and the group moved off the stairs onto the lower landing. There was little to be seen except another door leading away from the previous door.
Arya looked at the doors with a sense of foreboding. Normally, this kind of stuff never bothered her; she just went on regardless. She called for a halt to eat and rest a bit before they tackled what was behind these doors. The doors opened inward towards them, so they needed to block them. Tormund put his back to one of the doors, saying, "It will take them some time to move me." Brienne sat against the other, and they broke out the pack and their rations and ate. Hassan put his ear to the door and said, "There are 10-12 of them moving around."
They rested for a couple of hours, talking about how long exactly they had been inside. 4 hours or 20, they couldn't decide. At last they agreed they were all rested and stood to move forward. Intevar told Tormund to open the door long enough for him to cast his blinding light spell, and then they could rush in together. The door opened, and Intevar started casting. Coral spears came flying through the just-opened doorway. The spell was cast, and then Intevar was struck a glancing blow in the shoulder by a spear. Leland ran over to cast a heal on the small cut, and the spears stopped coming. They all rushed into the room.
It was a large chamber with a small pool in the middle. Above the pool was a large capstone to close the pool, hanging from a chain. Various Deep Ones were cowering from the blinding light spell around the room, but they were snapping out of it here and there. They seemed larger than the previous enemies, like they were upgraded fishmen. More scales dotted their bodies, and their coloring was slightly different. Shots rang out as Tormund put down as many of them as he could, walking down the wide stairs into the round room. Siora began casting offensive spells that wounded and killed Deep Ones; Arya was using her sword and glove to cast disruption spells around the room as well. Hassan dove into a pair of fishmen that had jumped out to counterattack them. He cut them down as he reached the bottom of the stairs. They were down to 4 of the largest enemies, and Brienne charged into the midst of them, swinging her sword with devastating effect. In seconds, the room was clear of enemies, and they breathed a sigh of relief. "Look at that," Arya said, pointing to what looked like a statue sitting on a throne.