The Mammoth Book of Historical Crime Fiction

The man on the boat said something, but he couldn’t make out what, and then the bigger man lifted down the woman and they all went up the stairs and headed for the building he’d thought was unoccupied. The big man was glancing around, as if to make sure no one was watching them. Robert kept very still.

Then, as clearly as St Paul’s bell, he heard the woman say “Is he in here? Will I see him now?” For answer, she was escorted in, and the door closed behind them.

He frowned. It couldn’t be. He must be imagining it. Were his brains still scrambled? But that voice — it sounded like Miss Byron. What could she be doing here? He began to struggle to his feet. He had to find a way to get inside — or at least see inside — that dilapidated building.

* * *

“Are you telling me the truth, Mr Babbage? She has not come here to your house? And you know nothing of any romantic liaison?”

“Believe me, Lady Byron, I’m as worried as you are. She has not come here, and I’ve not seen her since she was last here several days ago. As for romance — we confine our discussions strictly to science and mathematics, and matters of the higher mind.”

Lady Byron bit at her knuckle as she wandered to and fro in Babbage’s drawing-room. “Then where can she be?”

“How long since she disappeared?”

“Four full hours. She’s never been a robust child, and without proper care she might easily fall ill. Where has she gone? I hope the foolish girl did not have romantic notions. I’ve seen her reading The Times Personal columns, but she assured me — ”

“Ah, that would be because of me. We were — testing out a new code.”

“So she was telling the truth.” Lady Byron sank into a chair and put her head in her hands. “She can’t have … it’s too much to think … it can’t be in her blood … the water — ”

“I’m sure she has not taken her own life,” Charles declared bluntly. “She was too engaged in our mathematical studies. There is only one answer. She must have departed by boat. Yet no one saw her?”

“Her tutors did not see her on any of the boats passing by. Only her purse was lying on the ground.”

“Do you have it with you?” It was clear now to Charles that Ada has been abducted and hidden on one of the passing boats. If she’d gone by choice, she would not have dropped her purse. Had she left it on purpose? Might there be some clue about it?

Lady Byron opened her own bag and handed the purse to him. “I showed it to the police, but they did not need to keep it.”

Charles also sat down, and opened the clasp of the yellow satin bag then emptied the contents on the mahogany occasional table in front of him. He stirred them with his forefinger. A handkerchief with the initials AB entwined in red embroidery in the corner. A tortoiseshell comb. A small mirror. For some reason he thought of his beloved daughter Georgiana, so much missed, and his eyes misted over. Ada could not be a substitute for her, but he felt the same fatherly protective instincts for her as he had for his daughter.

He blinked. There was also some paper. He opened it up and recognized the elements from the fourth quadrant, whose solution had so far eluded him. Her busy mind had been working hard on them. He scanned her notes and suggestions, and the back of his neck suddenly prickled with excitement. She’d written “Proportions?” and what was this, a decorative necklace?

Of course! His mind leapt ahead and reached the conclusions she had not. But then he’d been blinkered by following the normal code-breaking routes, whereas she had made a sideways leap of the imagination.

“Lady Byron, may I take this? I have a contact who may be able to help us.”

“Anything — but hurry. Her reputation! Poor girl.” She gave a sob.

“Please wait here. I’ll send a messenger as soon as I can.”

Hatless and shrugging into his coat as he ran downstairs and out into the street to hail a hansom cab, his mind worked feverishly. Even though Ada had crossed through her workings and written “hopeless”, he was sure she’d made the right connection. The other 75 was saltpetre — combined with 10 parts of sulphur and 15 of carbon, it formed gunpowder. If so, then could the jewels on the other side of the equation be a ransom? Pay me a King’s ransom in jewels, or Wanstead Abbey would suffer the same fate as Parliament! Was that what the Prankster was threatening? No, why bother to blow up Wanstead Abbey? It had to be some other ecclesiastical building — and where else to make a bigger mark than St Paul’s Cathedral!

* * *

Robert crouched on the outhouse roof to regain his breath before testing the stability of the drainpipe above him. He’d first tried knocking at the door of the building, and, when the big fellow with wild woolly hair had opened it, he’d said, “Any knives need sharpening? Any rags you want got rid of?”

“Piss off or you’ll be buried so deep, even the mudlarks won’t find yer.” And the door was slammed in his face.