Lina, Doon, and their classmates got their assignments for work. Lina draws Pipework Laborer. Doon gets Messenger. Doon wants to be in the Pipeworks. So, they trade jobs and go home happy.
One day, Poppy, Lina's sister finds a random document. Lina takes it to Doon to see what it means. It takes a while to figure the document out. Along with some help her friend, Clary, they figure it out
Lina and Doon sort out what the document means: there's a way out of the city. The title for the document: Instructions for Egress. They plan to tell everyone at the Singing. But, little did they know, there was a small problem.
The guards thwart their plans and arrest Lina. As she was about to be moved to her cell, the lights went out. She escaped, got Doon and Poppy, and left the city. It was a bumpy and scary journey.
During their escape, Doon, Lina, and Poppy, saw that they were the underground the whole time. Before this, there was a climb that was difficult. Our friends went outside and explored a little.
They decided to throw a message to the people of the city. It basically said: Escape through the pipeworks. They threw the message into the city. Mrs. Murdo, who was walking faster than normal, picked it up off the ground and read it.