“Kerosene lanterns.” Janson gestured toward them. “Before the place was electrified, it would have been the primary source of illumination. The governor general’s compound would have had a kerosene tank in the basement, something that would be filled from outside. He’d want to have a plentiful supply of the stuff.”

“They might have ripped it out,” Katsaris noted. “Filled it with cement.”

“Possibly. More likely it was left to rust, quietly. The subfoundation level is vast. It isn’t as if they would have needed the space.”

“Vast is right. How are we going to find it?”

“The blueprint has a tank positioned approximately two hundred meters in from the northwest retaining wall. I hadn’t realized what it was for, but it’s obvious now.”

“That’s some distance,” Katsaris said. “Is the woman going to be up to it?”

Donna Hedderman gripped the iron bars to help herself stay erect; clearly, the period of relative immobility had weakened her muscles, and her still considerable girth gave them a great deal to support.

Novak looked at her and turned away, embarrassed. Janson understood the kind of relationship that developed between two deeply frightened prisoners who might not be able to see each other but could communicate, whispering through pipes, tapping code on metal bars, passing notes scrawled with grime on scraps of cloth or paper.

“You run ahead, Theo. Let me know when you’ve located it, and I’ll bring the others.”

Three minutes elapsed before he heard Katsaris’s triumphant words in his earpiece: “Found it!”

Janson looked at his watch: further delay was dangerous. When might the next contingent of guards arrive to relieve the ones who had been on duty? When would they next hear the scrape of the steel grate on the stone landing?

Now he led Peter Novak and Donna Hedderman along the dank subterranean corridor that led to the old kerosene tank. Hedderman held on to Janson’s arm as she walked, and even then her gait was slow and painful. These were not the cards he would have chosen, but they were the cards he had been dealt.

The tank, obviously long neglected, had an iron door with lead flanges to maintain a tight seal.

“There’s no time,” Janson said. “Let’s kick the damn thing in. The hinges are already rusting off. They just need help.” He made a running start toward the door, throwing up a foot as he reached iron door. If the door did not give way, the result would be a bone-jarring experience. But it did, collapsing in a cloud of dust and oxidized metal.

Janson coughed. “Get out your Semtex,” he said.

Now Janson strode through what had once been a storage tank for kerosene. The copper-lined chamber was still suffused with an oily smell. The fill hole was almost hidden by the hardened tarlike residue that covered the walls—impurities of the kerosene, which remained after many decades of disuse.