Dan closed his eyes and thought about where they were going to, and then nodded. There was the furnace and the boiler beside each other, and the long room full of papers, the pipes for the plumbing and heating, and the workings of the elevator.
(this way) he sent, turned on his flashlight and set off.
Once they left the light, the sounds of the boiler became more than obvious, groaning and creaking away. Dan was more than a bit afraid of it.