before he’d start feeling the effects. That’s why they use halon in occupied places. And before the gas is discharged, a warning horn comes on. We’re changing systems actually but not because it’s dangerous.”
“Why, then?”
“Halon significantly depletes the ozone layer. In fact, while it can still be used in this country and recycled for new applications, the manufacture of halon 1301 is banned in the U.S. and has been since the mid-nineties. Although the federal government is still the biggest user of it.”
“You seem to know a lot about halon.”
“Well, all employees were given an in-depth review of the system when it was first installed. And I did some extra reading on the subject.”
“Why?”
He blurted out, “Because I come into this vault a lot, and I didn’t want to die a horrible death! You know I lack any shred of personal courage.”
Stone examined the nozzle. “Where’s the gas stored?”
“Somewhere in the basement level of the building, and the gas is piped up here.”
“You say it’s stored as liquid and then comes out as a gas?”
“Yes. The speed with which it’s blown out of the nozzle turns it into a gas.”
“It must be very cold.”
“If you’re standing in front of the nozzle, you could get frostbite, in fact.”
“Anything else?”
“Well, if you stay in the room long enough, I suppose you could be asphyxiated. The rough rule of thumb is if there’s not enough oxygen for a fire, there’s not enough oxygen to sustain life.”
“Could the gas cause a heart attack?”
“I don’t know. But it doesn’t matter. The system never came on. That horn can be heard throughout the building. The only way Jonathan wouldn’t have heard it is if he was already dead.”
“What if the horn was disconnected?”
“Who would have done that?” Caleb said skeptically.
“I don’t know.”
While he was talking, Stone was staring at a large register built onto one of the columns supporting a bookshelf. “Is that a vent for the HVAC system?” he asked. Caleb nodded. “Something must have fallen on it,” Stone said, pointing to where two of the vent grilles had been bent.
“It happens with people bringing book carts in and out.”
Stone said, “I’ll have Milton research the halon system and see if anything else turns up. And Reuben has some friends at D.C. Homicide and the FBI from his days in military intelligence. I’ve asked Reuben to call them to see if he can find out something about the investigation.”
“We have the meeting with Vincent Pearl tonight at Jonathan’s house. In light of these developments, don’t you think it best to call it off?”
Stone shook his head. “No. Those men can find us wherever we are, Caleb. If we’re in danger, I’d rather try to find out the truth for myself than sit back and wait for the blow to fall.”
As they were leaving the vault, Caleb muttered, “Why couldn’t I have just joined a nice, boring book club?”
CHAPTER 22
THAT EVENING THEY ALL RODE to DeHaven’s house in Caleb’s Nova. In the meantime Milton had found out a lot about fire suppressant systems. He reported that “halon 1301 is odorless and colorless, and extinguishes fires by tweaking the combustion process, which includes the depletion of oxygen levels. It evaporates quickly, leaving no residue. Once the system is activated, it’ll discharge in approximately ten seconds.”
“Can it be lethal?” Stone asked.
“If you hang around long enough and depending on the concentration levels of the flooding agent, you can suffer asphyxiation. It can also cause a heart attack.”
Stone looked triumphantly at Caleb.
“But the autopsy result said he suffered cardiopulmonary arrest,” Milton reminded him. “If he’d suffered a heart attack, the cause of death would’ve been listed as a myocardial infarction. A heart attack or a stroke leaves very clear physiological signs. The medical examiner wouldn’t have missed that.”
Stone nodded. “All right. But asphyxiation can happen, you said.”
“I don’t really think so,” Milton said. “Not after I spoke with Caleb earlier.”
“I looked more into the library’s halon system,” Caleb explained. “It’s rated as an NOAEL system. That stands for No Observed Adverse Effect Level, a standard protocol used in fire suppression. It relates to the cardio-sensitization levels present in a particular place in relation to the amount of flooding agent required to extinguish a fire. Bottom line, with a NOAEL level, you’d have plenty of time to escape the space before being affected. And even if the horn were disconnected for some reason, if the gas had come out of that nozzle, Jonathan would’ve heard it. There was no way halon could have incapacitated him so fast that he couldn’t have escaped.”
“Well, it looks like my theory on how Jonathan DeHaven died was incorrect,” Stone admitted. He looked up ahead. They had just pulled onto Good Fellow Street.
“Is that Vincent Pearl?” he asked.
Caleb nodded and said irritably, “He’s early, probably very eager to prove yours truly wrong about the Psalm Book.”
Reuben smirked. “I see he left the robes at home.”
“Keep your eyes open,” Stone warned as they got out of the car. “We are undoubtedly being watched.”
True to Stone’s words, the same pair of binoculars from the window across the street were trained on the group as they met Pearl and headed into the house. The person also had a camera and snapped a few shots of them.
Once inside, Stone suggested that the rare book dealer accompany Caleb to the vault alone. “It’s not that large of a space, and you two are the experts in the area,” he explained. “We’ll just wait upstairs for you.”
Caleb looked unhappily at Stone, doubtless for casting him solo to Pearl. For his part Pearl gazed at Stone suspiciously for a moment and then shrugged. “I doubt it will take me long to show that it is not a first-edition Psalm Book.”
“Take your time,” Stone called to them as the two men stepped onto the elevator.
“Don’t let the book bugs bite,” Reuben added.
As the door closed, Stone said, “Okay, quick, let’s search the place.”
“Why don’t we wait for Pearl to leave?” Milton asked. “Then we can take our time and Caleb can help us look.”
“I’m not worried about Pearl. I don’t want Caleb to know, since he would undoubtedly object.”
They split up, and for the next thirty minutes they covered as much as they could.
Stone said in a disappointed tone, “Nothing. Not a diary, no letters.”
“I did find this on a shelf in his bedroom closet,” Reuben said, producing a photograph of a man and a woman in a small frame. “And that’s DeHaven next to her. I recognize him from his picture in the paper.”
Stone gazed at the photo and then turned it over. “No name or date. But judging from DeHaven’s appearance, it was taken many years ago.”
Milton said, “Caleb told us that the lawyer mentioned DeHaven was married once. I wonder if that was the bride?”
“Lucky guy if it is,” Reuben commented. “And they look happy, which means it was early on in the marriage. That all changes with time, trust me.”
Stone slipped the photo into his pocket. “We’ll just hold on to it for now.” He stopped and looked upward. “This home has a steeply pitched roof.”
“So?” Reuben said.
“So homes with a pitched roof of this vintage usually have an attic.”
Milton said, “I didn’t see anything like that upstairs.”
“You wouldn’t if the access were hidden,” Stone replied.
Reuben checked his watch. “What’s taking the book geeks so long? You think they’re fighting?”
“I don’t really see those two chucking first editions at each other,” Milton said.
“Whatever it is they’re doing, let’s just hope
they keep it up for a little while longer,” Stone said. “Milton, you stay down here and keep watch. If you hear the elevator, call up to us.”