The forty-third floor was not what she had expected, though she could not have said what she had expected.
Something more dramatic, perhaps. Tactical displays and people wearing earpieces, the visual grammar of a spy organisation from the films she had watched as a teenager. Instead: a wide open space with high ceilings, the kind of furniture that suggested someone with resources and taste had furnished it to look like neither. Bookshelves floor to ceiling on two walls. A kitchen visible through an archway, someone running a coffee machine. A long table with a dozen chairs, half of them occupied by people who looked up when she entered and then looked back down at their work.
Normal. Or the careful performance of normal.
Sienna directed her to a chair at the end of the table and set a glass of water in front of her without asking. Hilton sat across from her. Between them was a silence of the kind that had weight.
Della drank some water and decided to go first.
"The Enuma-Keth," she said. "What does it do?"
Hilton looked at Sienna. Sienna gave a small, almost imperceptible nod.
"It's a key," Hilton said. "Broadly speaking. It opens — or unlocks — something that has been sealed for a very long time. Thousands of years."
"What's sealed?"
"An entity. A power source. The Covenant calls it Ur-Namazu. Our records use half a dozen different names, depending on the historical period." He folded his hands on the table. "Whatever you call it, it should not be opened. The Covenant believes the power can be controlled. Every historical record we have suggests that belief has a consistent outcome."
"Which is?"
"The person who opens it gets what they want, briefly. Then the corruption sets in. Then the vessel is lost. Then the entity does what it was going to do anyway, without a vessel to direct it." He paused. "It does not go well for the surrounding population."
Della absorbed this. "And the Enuma-Keth is the key that opens it."
"Half the key. The artifact itself is only a mechanism. To activate it—" He stopped.
"To activate it," Della said, "you need something else."
"Someone else," Sienna said, which was different.
The room felt slightly differently configured than it had a moment ago. Della had the specific internal sensation of a thing she had been circling becoming visible.
"Me," she said.
Neither of them answered immediately, which was, itself, an answer.
"Your bloodline," Hilton said. "There is a lineage — the Threshold Line — whose blood interacts with the Enuma-Keth. Not metaphorically. Biochemically, in ways we don't fully understand. Your blood, in contact with the artifact, activates the inscription. The inscription, read correctly, opens the seal."
"My blood."
"Yes."
"And my mother?" Della said, because she had been thinking about her mother for the past forty minutes and had not yet decided how much that thought was connected to this room.
The silence was different this time. Specific.
"Your mother was also of the Threshold Line," Hilton said. "She knew what she was. She worked with us for several years."
"She died in a car accident."
"She died," he said, carefully, "in an incident that The Veil investigated."
Della looked at him. He held her gaze, and in it she could see the shape of what he was not saying — the same shape she had carried around for four years, which she had told herself was grief and which she was now understanding was something else. The specific weight of a question that doesn't have a satisfying answer because the answer is a door, and the door opens onto something you cannot come back from.
"The Covenant," she said.
"We believe so. Yes."
She put her hands flat on the table. She was surprised to find they were not shaking.
"What do you want from me?" she asked.
"For now — nothing." Hilton's voice had changed slightly; something in it had softened by a fraction, which she noticed because everything else about him remained precisely calibrated. "We want you safe. The Covenant knows you exist. They tried to take the artifact tonight because they thought they could get to you next. Without both components the Enuma-Keth is inert. But they're patient."
"And eventually?"
"Eventually," Sienna said, "we want to make sure the Enuma-Keth can never be used. Which means keeping you away from it, or — under controlled conditions, with your consent — finding a way to neutralise the seal entirely."
"Under controlled conditions," Della said. "With my consent."
"Yes."
"You're doing very well at saying that like you mean it."
A pause. Something moved across Hilton's expression — something almost like amusement, quickly contained.
"We do mean it," he said. "You are not an asset. You're a person who has been pulled into a situation not of your making. We understand that."
"Do you?"
"I do," he said, which was different from we, and she noticed that too.
She looked around the room. The people at the table were doing their work. The coffee machine had finished. Somewhere, her father was in a secure location with twelve Secret Service agents, fine, protected, unaware of what his daughter was learning in this room about the shape of her own blood.
"I have questions," she said.
"I know," Hilton said.
"A lot of them."
"I know."
"And I'm going to need more water."
He got up and got it, which she hadn't expected. She had expected him to gesture to someone else, or press a button, or demonstrate in some small way that he was above the task. Instead he went to the kitchen himself and came back with the water and set it in front of her without comment.
She picked it up.
"Start from the beginning," she said. "Tell me everything."
He sat down. He began.