"Yes, of course that's what I mean, you bloody fool!"
"Steady, man. Calm down. Remember that you're my guest here."
Oxford wrapped his arms around himself and gazed at the marquess.
"I killed a man," he whispered.
"You did what? When?"
"Three years from now. I killed a man by accident. He was my ancestor."
"Good Lord! Sit. Tell me more."
Oxford shuffled to a chair and fell into it. He stared at the floor.
"Henry, imagine that time is a cord stretching forward from now all the way to the year 2202. Now picture a point on that cord a short distance ahead of us-the year 1840. There is a man at that point whose name, like mine, is Edward Oxford. We'll call him the Original Oxford. As you move along that line, you see this man fathering a child, and that child grows and becomes parent to another, and that one does the same, and so on and so forth until you reach 2162, when a descendant of the Original Oxford gives birth to me."
"I get the picture," said Beresford. "So what?"
"Now move forward to 2202, my fortieth birthday. I jump back from that far end of the line to 1840 and I kill the Original Oxford before then jumping to the start of the line, where we are now."
"The present moment," offered the marquess.
"Yes. Now, at 1840, the line has been cut. The stretch of it containing all the Original Oxford descendants is no longer joined to the part of the line that we are on. It still exists, perhaps, but not for us. For us, everything after the death of the Original Oxford must be written anew. There's nothing there for me to jump forward into!"
"But you went to 1877. That's beyond the cut!"
"Yes, it is, and I've been puzzling over that all night. I think I know what happened. I think I jumped to the end of my natural life span."
"I don't understand you."
"Henry, if I remain in this time, by 1877 I will be eighty years old. Friday March 9, 1877, I am certain, will be, barring accidents, the end of my days."
"Do you mean to suggest that you can travel within your own allotted time, as it were, but to go beyond that you need a future which, for you, has already been established?"
"Yes, exactly."
"To all intents and purposes, then, you seem to have wiped yourself out of existence. But why, Edward? Why did you kill this man?"
"I'd rather not go into that. Like I said, it was an accident."
"So go and prevent it. If you can travel as far as 1877, then 1840 remains well within reach. Go and stop the death of the Original Oxford."
"Henry, don't you see? I'm here; I killed him; no one stopped me; therefore if I try, I will surely fail!"
"The complexities of time travel are far beyond me," answered Beresford, "but in the future you were alive and invented a time suit. That cannot have been possible if someone killed your ancestor. Yet here you are. It seems to me that just because you perceive that things occurred a certain way doesn't mean you can't go back and alter them."
Edward gazed into space.
"Yes," he whispered thoughtfully. "Yes, I suppose that's true. It's worth a try!"
He sprang to his feet.
"I have to work on the suit, Henry. There's damage to the helmet and the control unit requires further attention!"
"For pity's sake, man, rest first! You look as if you've not slept all night!"
"I haven't! There's no time for sleep!" barked Oxford, crossing to the table where his gear was laid out.
Beresford shook his head.
"Of all people," he said quietly, "I would have thought you'd have all the time in the world."
Three years later, Edward Oxford hit the ground running.
He was farther away from the other two Oxfords than he'd planned and, as he raced past a policeman, he realised that he was too late, as well; the two men were already locked together; the pistol was already raised toward the queen.
"Stop, Edward!" he bellowed.
Suddenly a bolt of energy flashed out of the control unit and into the ground. He doubled over in pain as the charge ripped through him and looked up again just as the pistol went off and Queen Victoria's head sprayed blood.
The monarch fell backward out of her carriage.
The Oxfords wrestled. The Original tripped and went down, his head smacking onto the railings.
It was me, thought the time traveller. The distraction; the shout and the flash. I looked up at myself here on the hill and in doing so moved my ancestor's arm. I caused the pistol to point at her head!
"No!" he groaned. "No!"
The control unit let loose a shower of sparks.
He turned.
The policeman had almost caught up with him.
Oxford sprang over the constable's head and landed back in 1837.
"I can't stop it!" he told Henry de La Poer Beresford as he entered through the veranda doors. "It might not have happened at all if I hadn't gone back just now!"
He dropped his face into his hands and moaned.
"Sleep," ordered Beresford. "Once you are rested, you'll think more clearly. We'll find a solution. And remember, you have forty years in which to work on it."
"Bloody hell!" cursed Oxford. "I can't stay a Victorian recluse for the rest of my life. Besides, my wife is expecting me home for supper."
He suddenly chuckled at the contrast-the extraordinary and the mundane-and lost control of himself, throwing his head back and laughing wildly, a harsh and unbalanced noise which caused the marquess to step back a pace.
It echoed through Darkening Towers, that horrible laughter.
Maybe it echoed through time.
DISSUASION
Nothing is permanent, least of all the thing you think of as I.
Edward Oxford raved all evening until Beresford summoned Brock and together they half pushed, half carried him up the stairs and into his bedroom. They pulled off his clothes-both had learned how to unfasten the time suit-and put him to bed. He eventually fell into a fitful sleep, muttering to himself, groaning, tossing and turning.
When he shuffled into the morning room the next day, he looked gaunt and fevered, with dark circles around his eyes.
"Eat," commanded Beresford, indicating the food the butler had placed on the table.
Oxford sat and ate in a desultory manner, his eyes glazed.
"I have a question," said the marquess.
His guest grunted.
"Where is your ancestor now, at this moment, June 1837?"
"He's fifteen years old. He lives with his mother and sister in lodgings at West Place, West Square, Lambeth."
"And where will he be when you kill him?"
"Green Park."
"Then you must go to Lambeth, find him, and convince him that he'll be murdered if he visits Green Park in 1840."
Oxford leaned back in his seat and looked at the marquess.
"Yes," he mumbled. "Yes. If I can manage it; if I can bear the exposure and hold myself together, it could work."
"Do you know where West Place is?"
"Yes, it's right beside the Imperial War Museum."
"The what?"
"The Imp-No, wait, that hasn't been built. It's-It's the Bethlem Royal Hospital!"
"Bedlam, you mean?"
"The very place where my ancestor will spend twenty-four years of his life if I prevent myself from killing him."
"He was-is, I mean-a lunatic, then?"
"At this point in time, 1837, he's beginning to show symptoms of mental disturbance. The illness reaches its peak in 1840, when he commits a criminal act. He's caught, tried, and committed to Bedlam. Over the next couple of decades or so, he recovers his wits, though he remains incarcerated. They eventually move him to Broadmoor, then he's freed and deported to Australia where he meets and marries a girl. They have a child who is my Idon't-know-how-many-times-great-grandfather. "