She bent down and peered at the bullet wound, pursing her lips. 'It appears the exercise has failed again.' She said curiously.

'Quite.' Her brother replied, picking up the box and wiping it of blood carefully. 'The assassin was quite thorough.' He remarked, lifting the cloth sack, staring at Booker Dewitt's lifeless face as he had over a hundred times before.

'This one never even made it into the rocket.' She said with a frown. 'I think this must be our fastest death yet.'

'He fell out of the boat twice.' Robert reminded her.

'Oh yes. I think we could have stopped him from drowning the second time if he'd not surfaced under the oars.' She looked pensively at the figure tied to the chair. 'Still more where that came from. We do, after all, have other places to have been.'

'I think we should give this universe one more try.' Rosalind glanced at him quizzically.

'Then shouldn't we dispose of the body, he might find it disconcerting to come face to face with his, well, face.' She asked.

'No, he's never going to have lifted the mask, and it might prove to be the motivation he had needed.' He paused, thinking through the syntax for a moment.

'Good point.' She agreed. 'How many Dewitt's now?'

'One hundred and twenty two.' He said.

'How many times did he never make it beyond this lighthouse?'

'Fourteen.' He frowned at her. 'I still think this is a venture worth pursuing.'

xxx

The first time Booker had stumbled through the doorway Rosalind had remarked on his hand, in every universe he had branded himself, that was a constant, the location of the brand, a variable. That's all this was to Rosalind, an experiment in the constants and variables of these lives, but to Robert, it was a way to seek repentance.

'Bring us… Bring us the girl… and wipe… wipe away the debt.' Those words were part of each experience now as they helped him into the boat.

'I'm starting to think you were much more harsh with him than you should have been.' She said to her brother.

'One has to have been harsh. You forget that I had as much to lose as he had.' That was the essence of his guilt, to have used this situation to meet Rosalind, to have been party to such corruption, he rowed a little more bitterly than the previous times. 'Are you going to just sit there?' He asked her peevishly.

'As compared to what? Standing?' She asked in a tone that was just shy of mockery, it was hard to mock someone who you knew was equally as intelligent as you.

'Not standing. Rowing.'

'Rowing?' She questioned, as she picked up the wooden box. 'I hadn't planned on it.' She turned and passed the box back to Dewitt.

'So you expect me to shoulder the burden?' He asked.

'No, but I do expect you to do all the rowing.' She remarked, Booker had asked something but it was lost to the wind.

'And why is that?' This conversation was a variable, they didn't feel too constrained by the probability space, but there were some things they adhered to.

'Coming here was your idea.' She said simply.

'My idea?' He asked, knowing full well that the lighthouse was a constant, a little puzzled at her comment.

'I've made it very clear I don't believe in the exercise.' She gave him a look from under her yellow hat that spoke volumes.

'The rowing?'

'No.' The tone of her voice changed slightly as her quick mind picked up a thought. 'I imagine that's wonderful exercise.' Behind her Booker was coming more to his senses.

'Then what?' Robert seemed dedicated to confusion in this conversation.

'The entire thought experiment.' Robert frowned at that, she was very vocal about her utter distaste for this when they could just let sleeping dogs lie and go about their lives as needed. Robert ultimately felt he must put right what once had gone wrong. It was important.

Booker said something that they ignored, once again going over this argument. 'One goes into an experiment knowing one could fail.' He reminded her, it didn't really do to talk of his death when he was sitting right there.

'One does not undertake an experiment knowing one HAS failed.' Robert nearly sighed at her, somewhere in the probability space there had to be a Booker that set this to rights, it was just a matter of finding him.

'Can we get back to the rowing?' He asked, feeling on safer ground there.

'I suggest you do, or we're never going to get there.' She replied flippantly, effectively trying to end the conversation.

'No. I mean I would greatly appreciate it if you would assist.' He said patiently, with a touch of irritation.

'Perhaps you should ask HIM.' She very rarely referred to him by name, Robert wondered if it was a way of distancing herself from what she had done. He was always 'him' or 'that one' to her. 'I imagine he has a greater interest in getting there that I do.'

'I suppose he does, but there's no point in asking.' Mostly because Booker didn't know exactly how much he wanted to get there anymore. Robert had offered him a chance to unite with his daughter, he had taken it and promptly forgot.

'Why not?'

'Because he doesn't row.'

'He doesn't ROW?' Rosalind asked in surprise, every man of their time had occasionally punted along the rivers.

'No. He DOESN'T row.' Robert said, indicating that no version of Booker had ever rowed or would ever row, also a constant.

'Ah, I see what you mean.'