"And, having just listened to Algy's story, how can we doubt that D, B, and N stand for Darwin, Brunel, and Nightingale?"

"By George! Now it seems obvious! And the 0 is Oliphant, who's being asked to confirm something about them! But who is the second B?"

"I don't know. We'll come back to that. As for what it is this mysterious B wants confirmed, the two sets of numbers give it away: it's a date and a time using the twenty-four-hour clock. The 29th of September at eleven o'clock in the evening. That's this coming Sunday night. A meeting, I'll wager."

"By Jove! You're as sharp as a tack. I'd have been mulling over this note for hours! How about the DTs?"

"Delirium tremens!" suggested Swinburne enthusiastically.

"Silly ass!" Burton smiled. "I'd say it represents the location."

"If there really is a connection between Spring Heeled Jack and Oliphant, as you suspect," said Trounce softly, "mightn't DTs represent Darkening Towers? It was, after all, the home of Beresford, who was suspected of being Jack, and who was also the leader of the Rake movement before he died."

"And Oliphant is his successor!" cried Swinburne.

Burton looked at the Scotland Yard detective with an expression of admiration.

"I'd bet my right arm that you've hit the proverbial nail slap bang on its head! "

"I'm not so sure," grumbled the inspector. "It may just be a coincidence."

"Possibly; but it's a big one. Which just leaves us with the letter B. Who was Beresford's successor to the marquessate? Did he have a son?"

"No, he died without issue and the marquessate became defunct. Dark ening Towers passed to his cousin, the Reverend John de la Poet Beresford, who runs a famine-relief organisation in Ireland and who hasn't ever set foot on English soil. He rents the property, through an agent named Flagg, to one Henry Belljar, a recluse of whom no record seems to exist. Flagg himself has never seen Bell jar; their business has always been conducted entirely by post. So there's your mysterious Mr. B, Captain Burton!"

"It would seem so," responded Burton thoughtfully. "I would very much like to see this Henry Belljar. In fact, on Sunday night, if 0, D, B, and N are going to have a confab with him at Darkening Towers, then I think a third B should be present, too-B for Burton!"

"If you mean to say that you're going to spy on them, then you can jolly well count me in!" cried Trounce.

"And me!" chorused Swinburne.

"No," said Burton sharply. "I'm afraid I have to pull rank on you, Inspector; while you, Algy, are in no fit state. One person can move more quietly than three and I have experience in this sort of business-I was a spy for Sir Charles Napier during my time in India and undertook more than one mission where stealth was required."

"You'll at least allow me to loiter nearby?" grumbled Trounce petulantly. "Just in case you require reinforcements? Surely, though, we could forego the spying and simply raid the place with a squadron of constables?"

"If we do that," responded Burton, "we might never learn the full extent of their plans or lay our hands on Spring Heeled Jack."

"I insist on coming along too!" squealed Swinburne, slapping his hands against the bedsheets. "I'll not be left out!"

"Mr. Swinburne!" exclaimed Sister Raghavendra. "You'll stay in bed, sir! You are in no condition to go gallivanting around on dangerous missions!"

"I have two whole days to recover, dear lady! I shall be perfectly fine! Richard, say you'll take me!"

Burton shook his head. "You've contributed more than your fair share to this business, my friend. You nearly got yourself killed."

Swinburne flung back the sheets and scrambled upright, standing on the bed in oversized pyjamas, bouncing slightly, twitching and jerking with excitement.

"Yes!" he cried. "Yes! I was nearly killed by that fiend! And do you know what I learned from the experience? I learned-"

He threw his arms out and nearly overbalanced. Everyone stood and moved to catch him but he recovered himself and proclaimed:

"How he that loves life overmuch shall die

The dog's death, utterly:

And he that much less loves it than he hates

All wrongdoing that is done

Anywhere always underneath the sun

Shall live a mightier life than time's or fate's."

His knees buckled and he fell against the wall, slowly sliding back down onto the bed.

"Goodness," he exclaimed weakly. "I think I stood up rather too quickly!"

Sister Raghavendra grabbed him by the shoulders, manoeuvred him back into the bed, and tucked the sheets around him.

"Foolish man!" she snapped. "You're too exhausted to go jumping around on a mattress, let alone chasing after mysterious Mr. Belljars. You'll stay put, sir, and you'll drink beef broth three times a day; isn't that right, Mrs. Angell?"

"Even if I have to sit on him and pour it down his throat," answered the old housekeeper.

"Richard! Am I to be a prisoner?" pleaded the young poet.

"For two days at least," confirmed his host. "We'll see how you are on Sunday. Sister, will you visit?"

"Certainly, Captain Burton. Mr. Swinburne is my patient; I will attend him daily until he is well."

"Bliss!" whispered Swinburne.

"And Captain," added the young nurse, "if there's any other way I can help, please don't hesitate to ask!"

Detective Inspector Trounce picked up his bowler and dusted a flake of soot from its brim. Mrs. Angell watched it float to the floor. She pursed her lips disapprovingly.

"I'll call again tomorrow, Captain," announced the Yard man, pacing to the door. "We'll go over our plans for Sunday night. But, I say, do you think this Mr. Belljar chappie is our jumping Jack?"

"I have no idea, Inspector," muttered Burton. "But I intend to find out!"

Darkening Towers well suited its name.

Lying a little beyond the village of Waterford, near Hertford, the estate was some forty or fifty acres in extent, and was entirely surrounded by a high wall of rotten grey stone. Within this crumbling barrier, the ground stretched unevenly, with large areas slumped into damp, pestilent hollows, as if being eaten away from beneath. These depressions were filled with a sluggishly writhing vapour that possessed a green-tinged luminescence, and over them decayed and contorted trees squatted blackly in the moonlight, casting weird shadows and making surreptitious movements. Upon the contaminated soil grass grew in fitful clumps and weeds, brambles, and tendrils twisted hither and thither as if their existence was an unavoidable agony.

In the middle of all this crouched the half-ruined mansion.

Built on the foundations of a Norman manor house, the glowering edifice was terribly dilapidated; its entire west wing had been ravaged by fire at some point and was nothing but a mildewed shell, while the habitable part of the mansion had sagged, opening fissures in its vine-clad, mouldering face.