The mirror led to an unremarkable corridor of stone and mortar. Windows opened on views of foreign planes, some recognizable, some not. At the end of the hall stood another door that opened on what looked very much like the house they’d just left.
“This leads to Dis,” Kal said. “Let’s hurry.” He stepped forward through the door, or tried to, colliding with a seemingly solid wall. “Ow,” he complained.
“Did you wish me to open the mirror?” Mal asked.
“Please!” Kal said. They climbed out on Mal’s bed and down the stairs.
“Let’s go,” Sheen said. “The Jester’s Palace is a good distance from here.”
The street outside was the same as the Smith Street in Sigil, but it was filled with war. Everywhere devils were struggling against demons, surrounded by hordes of panicking petitioners.
“Oo, a party!” Mal announced.
Haden scoped out the street and led them through twisted back alleys. As they traversed the Lady’s Ward they could see that the buildings were incomplete. The building facades were mostly complete, but the back alleys were empty and sterile, unlike the real Sigil. They crept out into Bloodgem Road, across from the temple of Shang-Ti. At the end of the road, near the park, a pit fiend battled with a swarm of familiar-looking four-winged, hawk-headed demons—Aspects of Pazuzu. They hurried across the street, petitioners racing past them. They emerged again near the Prison, where a blind and enraged demon over thirty feet high had smashed a hole in the wall, allowing a horde of petitioners to run free. One of them, a human woman, approached the group and stopped.
“Talan? Is that really you? It’s me . . . it’s Therya.”

(image by Sam Wood, from Monster Manual v.3.5 