Free Vector by Robin Cook

level in the machinery spaces was horrendous. It was a huge room that was filled with all manner of equipment, including massive electrical panels, huge boilers, compressors, and pumps. A bewildering array of pipes, ducts, and conduits angled off in all directions. Few people ever paused to think of what it took to warm and cool a building the size of the Jacob Javits Federal Building or for the elevators to function or even for water to come out of a faucet on the thirty-second floor. It all required a lot of power and machinery, and it ran twenty-four hours a day.
    The main air ducts were so large they didn't look like ducts. They ran along one wall of the oversized room before branching off like a large, felled tree. At intervals there were hatch-like doors that were dogged like those on a ship.
    Reggy had to shout to be heard. He pounded the side of one of the ducts and yelled that it contained the fresh air being pulled in from outside.
    He showed where it mixed with recirculated air.
    Reggy walked along the duct, then pounded it again. "Here's where the filters are located, " he yelled. "What part of the duct do you want to #, , see.
    "The part downstream from the filters, " Curt yelled back.
    Reggy nodded. He walked over to a huge circuit breaker switch and threw it. A portion of the cacophony of machinery noise in the room wound down.
    "That's the switch to the main circulating fan, " Reggy explained.
    Then he walked over to one of the hatch-like doors and undogged it. It opened into the room on creaky hinges.
    "We're upstream of the main circulating fan, " Reggy said. "When it's running you can't open this door. There's too much suction." Curt moved to the door and glanced into its dark interior. He slipped his flashlight from its holder on his belt and turned it on. First he directed the beam back at the filters. Steve tried to see over his shoulder, but the door was too narrow.
    "Step inside if you'd like, " Reggy suggested.
    Curt ducked down and stepped over the lip. He shined the light back at the filter. Steve leaned in from the doorway. Reggy went over to the HVAC console to turn off the alarm announcing a fall in the system's pressure.
    "See what I mean about the need to reconnoiter, " Curt said. The insulated duct shielded most of the noise coming from the machinery room.
    "I forgot about filters, " Steve admitted.
    Curt swept the light in the opposite direction. The huge blades of the main circulating fan were still slowly revolving. Angling the light up to the ceiling, Curt found the smoke detector. He'd need a ladder to test it.
    "That's the one we'll want to go off, " he said. "We'll have to find an accessible air return on this floor for one of the troops to set off a smoke bomb."
    "You think there's a specific designator for this smoke detector on the fire control annunciator panel? " Steve asked.
    "I'll be surprised if there isn't, " Curt said. "And even if there isn't, the panel will tell us the activated smoke detector is in the HVAC system. One way or the other you and I will have a reason to come in here."
    "Provided we beat Engine Company Number 6 from Beekman Street, " Steve said.
    "There's no way they could get here before us, " Curt said. "Engine Number 6 has to come from the other side of City Hall. We'll be in this duct before they even reach the scene. If we have to worry about anybody, it's our own ladder company. We just have to be sure they keep themselves busy getting all the elevators down to the ground floor like they're supposed to."
    "So what do we do when we get in here? " Steve asked. "Where do we put the stuff? " He glanced around at the floor of the duct. There was no place to hide anything.
    "Yuri says it will be in the form of a fine powder in impervious plastic bags. We'll just place them in here and set the little timed detonators.
    When they go off, we'll be long gone."
    "You don't think we have to hide the bags? "
    "I don't see why, " Curt said.
    "What if someone comes in