“Why do you say that?” Joanna asked. “What’s on it?”

Fred gave her a lopsided grin. “It’s code, all right,” he said. “I don’t know where you guys got this, but if the Feds knew you had it, they’d probably shit a brick. Excuse me, Sister,” he said again, eyeing Sister Celeste. “I keep forgetting.”

“What is it?” Joanna asked.

“It’s military code,” he said. “It’s the kind of thing they use for command and control procedures. And even though it’s out of date, I’m sure it’s still classified. They don’t like to let any of this stuff out because inevitably, one set of encryption codes is built on top of another. If you have one of the base codes, you can usually extrapolate from there and figure out what’s going on.”

“So,” Frank asked. “Can you tell us anything about this?”

Fred Woodworth smirked and shrugged. “Some. Compared to where we are now, this is pretty primitive stuff. I’d say these files date all the way back to the late eighties or early nineties. I can’t say which branch of the service the files are from, but since Fort Huachuca is right next door here, my first guess would be army. If you want to know anything more about this, I’d suggest you call them.”

Across the table from Fred Woodworth, Sister Celeste let out a long, audible sigh. “It’s true, then,” she murmured.

“What’s true?” Joanna asked.

“What Lucy Ridder told me.”

Joanna held up her hand. “Wait,” she cautioned. “Don’t say anything more right now. Mr. Woodworth? Mr. Davis? Thank you so much for all your help, but I believe that’s all we need for right now. If there’s anything more, we’ll let you know.”

Now it was Fred Woodworth’s turn to sigh. Closing the lid on the laptop, he ran one finger regretfully and lovingly across it. “It was a pleasure,” he said. “I’ll be glad to help out anytime. Just give me a call.”

He and Rich Davis stood up. Frank Montoya escorted the two men as far as the conference-room door. As soon as they stepped over the threshold and out into the reception room, Frank closed the door behind them and turned expectantly back to Joanna and Sister Celeste.

“What did Lucy tell you?” Joanna was asking.

“That her mother was a spy.”

“A spy?”

“She said her father told her that Sandra Ridder was providing top-secret information to our enemies. I’d guess that would have been the Iraqis during the Gulf War.”

For a second or two, both Joanna Brady and Frank Montoya were struck speechless. Before either one of them could comment, Sister Celeste stood up. “I’m sure you’ve heard enough,” she said. “Now, if you’ll be so good as to come with me, I’ll take you to Lucy right away.”

“Where is she?” Joanna choked, finding her voice at last.

“At Holy Trinity Monastery over in Saint David,” Sister Celeste said. “The prior, Father Mulligan, is a good friend of mine, and I understand he’s a friend of yours as well. He promised me he’d take care of Lucy and keep her safe and out of sight. Lucy Ridder is convinced that the man who murdered her mother came out to Cochise Stronghold that night looking for the computer disk. She’s afraid that eventually he’ll figure out who must have it. Once he does, he’ll come looking for her as well.”

“Wait a minute. Are you saying Lucy knew someone killed her mother?” Joanna asked. “How could she?”

“It’s perfectly simple,” Sister Celeste answered calmly. “Lucinda Ridder saw him do it.”

With Frank holding the door for her, Sister Celeste brushed past him and out of the office. For a time, Joanna made no move to follow. When she didn’t, Frank pulled the door shut once more. “Do you want me to come along?” he asked. “To Saint David, I mean?”

Joanna shook her head. “I don’t think so. I want you to get Detective Carpenter to tackle the Fort Huachuca situation ASAP. Tell him I want to know everything possible about Sandra Ridder’s position when she used to work on post-who she worked for, what she did, how much money she earned, everything.”

“Wait a minute,” Frank cautioned. “If this really does turn out to be a legitimate spy case, won’t we be stepping on jurisdictional toes?”

“Look at how old this case is, Frank,” Joanna said. “It’s been around at least as long as Sandra Ridder was in prison and probably a whole lot longer than that. What makes you think we’re the first ones to discover it?”

“You’re saying there may have been a cover-up?”

Joanna shrugged. “It could be. Look at what happened at Los Alamos. Let’s solve Sandra Ridder’s homicide before we send out for reinforcements and before we go jumping through any unnecessary bureaucratic hoops. If, in the process of doing that, we come across real evidence of espionage, then we’ll pass it along to the Feds so they can follow it up. In the meantime, we’re operating on hearsay eight-year-old evidence from a fifteen-year-old runaway and on the shaky technical assumptions of a convicted computer hacker. Talk about leaning on a pair of bent reeds. If we tried to call in the FBI based on what we have up to this point, they’d laugh themselves silly.”

“Sister Celeste could have it all wrong,” Frank suggested quietly.

“What do you mean?”

“Just because Sister Celeste thinks Lucy Ridder didn’t kill Sandra Ridder, that doesn’t necessarily make it true. Lucy may have lied to Sister Celeste, and she may lie to you as well, to say nothing of being potentially dangerous. Everybody seems to keep forgetting the kid has a gun.”

“If Lucy Ridder killed her mother, who killed Melanie Goodson?” Joanna asked. “Are you suggesting that Lucy is responsible for that murder as well?”

“I don’t know,” Frank said. “I suppose it’s possible.”

“But not very likely,” Joanna returned. “Somebody out there has gotten away with something for years. Once Sandra Ridder was let out of jail, maybe she threatened to blow the perp’s cover. That’s why Sandra Ridder is dead, and I’ll bet that’s why her attorney is dead as well. I’m with Sister Celeste on this one. I don’t think Lucy had a thing to do with her mother’s death other than possibly seeing it happen. And based on that-on the fact that she’s both an eyewitness and thought to be packing around a computer disk full of classified material-I believe Lucy Ridder’s life is in danger. Maybe her grandmother’s is as well. Speaking of Catherine Yates, hadn’t we better do something about her? Presumably, thanks to Sister Celeste’s efforts, Lucy is safe at the moment. I want round-the-clock surveillance on Catherine Yates’ place. That way, if someone comes there looking for the disk, we might just nail them.”

“Mounting a round-the-clock guard is going to cost money,” Frank said. “Are you sure you want to do that?”

“Thanks for your budgetary concern, Frank. But if it’s a choice between spending money or possibly saving a life, I’m in favor of the latter.”

“All right,” Frank agreed after a moment’s hesitation. “I’ll go round up Ernie, and we’ll get started. But what about the disk?” He held it out to her. “It’s evidence, isn’t it?”

Joanna nodded. “The question is: evidence of what? Bag it, log it, and take it down to the evidence room. Somebody somewhere is going to want it eventually. When they do, I want to be able to lay hands on it at a moment’s notice.”

“Unlike Tucson PD and a certain missing bullet,” Frank said.

“Right,” Joanna returned. Frank Montoya opened the door once again. In the reception room, Joanna found Sister Celeste pacing impatiently back and forth in front of Kristin’s desk. “Would you like to ride with me?” Joanna asked. “Or would you prefer to bring your own vehicle?”

“I’ll ride with you if you don’t mind,” Sister Celeste returned. “We need to talk. On the way, I’ll tell you what I know.”

Joanna was surprised by the nun’s response, but gratified as well. Sister Celeste may have had reservations about Joanna when she first appeared in the office, but those concerns had evidently been dealt with. Out in the parking lot, Joanna walked past her worn Blazer, choosing instead to drive Sister Celeste in the relative comfort of a departmental Crown Victoria.