“I’m sorry to disturb you.” Beth felt the folder under her cardigan nearly burning through her blouse. “I need to get into Dilly’s study.”

Thank God Mrs. Knox was a woman accustomed to not asking questions. She led Beth inside, toward the library. It was nearly dark; when she switched on the lamp, the pool of yellow light threw shadows like gargoyles across the shelves of books. Beth looked at the cracked leather armchair where Dilly had so often sat, and nearly wept. Dilly, why did you have to die? It all would have been easy if he were alive. He’d have known what to do with the dynamite she’d decrypted.

But Dilly had been resting in his grave since last February, and Beth was on her own.

As soon as Mrs. Knox departed, Beth flung herself at Dilly’s desk. He’d kept the key on his watch chain for as long as Beth had known him; where was it now? She gave a sob of relief when her frantic fingers sifted through the piles of old paper and found a familiar small brass key. She went to the panel in the wall and swung it out on its invisible hinge to reveal the safe. A turn of the key, and it opened—empty.

Slipping the folder of Rose-ciphered messages out of her cardigan, Beth hesitated. Most of them were still unbroken—she was tempted to take over Dilly’s desk and see if she could crack any more. But time was slipping away, and she had to be back at BP by midnight. She looked at the first report, the only one she’d broken. The beginning was garbled and hadn’t come out, but the message’s middle lines in English were clear. She already had them memorized.

—possibility is intriguing, but for now we have our own methods. Please convey our thanks to your source inside ISK and assure our continued interest in any further information. The usual compensation.

There was some sort of code name as a signature, a word Beth didn’t know. That wasn’t the part that had frozen her to her marrow when she read it.

Your source inside ISK.

These weren’t just dummy messages. Someone inside Bletchley Park had been passing information . . . and given the age of this traffic, they’d been doing it since ’42.

“Did you suspect?” she whispered aloud, looking at Dilly’s chair. But her simulacrum was silent tonight. Surely he hadn’t realized—if the secrecy of Bletchley Park was compromised, the Rose cipher would have been assigned its own section, not left to a dying man in his private library. No, Dilly had only taken it on because Rose was different, interesting, an anomaly. His last puzzle.

My puzzle now, Beth thought, and locked the folder away, closing the wall panel over the safe. If something as secret as Enigma decrypts had to be taken off Park property, at least the Knox safe had already been approved as a secure location. Beth didn’t dare take it back to Aspley Guise, and she couldn’t leave it at ISK, either.

Someone there was a traitor.

Who? she thought in a twist of utter wretchedness—because they were precious to her, every single one. Peggy, who had taught her how to rod; Giles, who said she was the best cryptanalyst he’d ever seen and didn’t sound resentful admitting it; Jean and Claire and Phyllida and all the rest of Dilly’s team who had worked with her on the Matapan crisis . . . one of them was selling information from Bletchley Park?

The usual compensation.

Beth’s stomach churned sickly.

She looked at the safe’s key, then slipped it into her pocket. Dilly had often joked that he really should have more than one safe key; if he ever lost this one he’d be up the spout. The Rose file could sit there until Beth could bring it to Commander Travis, whenever that might be. If he won’t see me tonight, then he’ll see me the hour the invasion is over, for better or worse. No later. Beth didn’t care if she had to hack her way into his office with a fire ax; he was going to give her a hearing.

“Finished, dear?” Mrs. Knox asked as Beth slipped out of the library.

“Yes. Please don’t tell anyone I was here. I left something in the library . . . don’t look for it.”

“Of course not.” Dilly’s wife looked unfazed.

Beth hesitated, then reached out and gave Olive Knox a hard, brief hug. “Thank you.”

Mrs. Knox’s elderly man-of-all-work nodded at Beth as she came out to the front drive. “Where to, miss? I’m to give you a lift.”

Beth was about to say Bletchley Park, but a familiar dull ache had bloomed low in her belly, and she felt a dampness on the back of her skirt—her monthly had begun. If she was going to be working a double shift starting midnight, then she’d need a sanitary towel. “Aspley Guise,” Beth told the driver, and battled a wave of utter weariness. How much she hated being a woman sometimes: underpaid and underestimated and betrayed by your own body. She wanted to storm into BP and shout at the top of her lungs that they had a traitor, damn it, and everyone had better listen—but would they listen to a woman with blood on her skirt? So many men seemed to think women were crazy when they were bleeding.

She dragged herself up the stairs at Aspley Guise, fighting off the cold waves of suspicion as her mind turned from one ISK colleague to another—It can’t be you—Could it be you?—How could it be you!—and let herself into her shared room. Osla was at the washstand scrubbing her face, and Boots looked up from his basket with a yawn. “Beth,” Osla greeted her, “is something going on? I had a telephone call, something about Mab and Coventry . . .”

Beth was rummaging for her little bin of sanitary supplies, but she straightened with a sudden surge of nerves. “Coventry?”

“I couldn’t really make sense of it—”

Mab stalked into the bedroom that she had once shared with the two of them, and not set foot in since her husband and daughter had died. Beth turned, barely in time to notice Mab’s blazing eyes before her friend struck her savagely across the face.

Chapter 64

You knew.” Mab threw Beth back against the wall. The rage was choking her, rising in her throat.

“Mab—” Beth tried to fend her off, but Mab was head and shoulders taller, fueled by fury. She banged Beth into the mirror, setting it rocking, and Boots leaped out of his basket barking. Then Osla seized Mab by the shoulders and wrenched her away.

“Mab, stop. What’s this about?”

Beth hunched frozen, arms about herself, Boots pressed to her ankles. Mab stood on the hooked rug, shuddering with anger. Osla poised between them, tiny and determined. For once, Mab felt no tangled confusion of anger and pain, looking at Osla. In Coventry, Osla had made a mistake—that mistake had let Lucy slip into the void, and Francis after her, but it had been a mistake.

Beth had made a choice.

“Tell her,” Mab rasped, looking at Beth. “Tell her about Coventry.”

“I don’t have time for this,” Beth begged, hands twisting. “I have to get to BP.”

She made a move toward the corridor. Mab crossed to the bedroom door, slamming it shut and standing before it. “What is happening here?” Osla demanded.

Mab waited, but Beth stayed silent, huddled in on herself. “I was told Beth broke a report about the Coventry raid. The one that killed—” She couldn’t force the names out. “She knew the attack was coming, hours before you and I left to meet Francis there with Lucy. She let us go without a word.”

The accusation sank into the room like a stone in a pool, spreading ripples.

“Beth wouldn’t—” Osla said, at the same time Beth whispered, “How did you find out?”

“Your friend Peggy, why does it matter? Is it true?”

Beth’s head jerked up. “If I’d told you it would have compromised—”

“No, it wouldn’t!” Mab cried. “We said goodbye to you at the BP canteen that same morning—no civilians in earshot, safe Park ground. You didn’t have to give details. All you had to say was ‘Please trust me and call off the visit.’” Mab would have telephoned Francis, asked him to meet them elsewhere. He’d be alive today. Lucy would be alive.

“I couldn’t tell you,” Beth repeated, pleading. “How could I put you ahead of everyone at Coventry who would have to sit the raid out, unknowing?”

“Because in a war, Beth, you save who you can. Whenever you can. You couldn’t have safely warned Coventry, but you could have safely warned us.”

“And you’ve done that before.” Osla’s voice was very quiet. “Autumn of ’Forty, you let us know when the German invasion was postponed.”

Beth flinched. “That’s why! I told you about the invasion, and I shouldn’t have. I swore I wouldn’t ever do it again. Besides, that’s different—you knowing the invasion was canceled changed nothing. But if you knew about Coventry, you’d tell Francis not to come, then he might tell his neighbor, they might warn someone else, then before you know it—”

“We wouldn’t have done that, Beth. Because we’d have lied to Francis. We lie to everyone—just not each other.” Osla was arrayed beside Mab now, arms folded like a shield. “Our knowing would have changed nothing, except that Francis and Lucy would still be alive.”