Allusions to their relationship, whatever its nature, were present even from Braxiatel's first appearance. The first real hint of it is given when Benny requires a research ticket for the Braxiatel Collection and the Doctor gives her his. The archivist, on seeing it, does not recognize it, so he calls up Braxiatel to ask what it is.

‘I’m sorry to disturb you, sir, but I have a research ticket here that I haven’t seen before.’

Benny strained to catch the response, but all she could hear was a tiny vibration as whoever Elliniko was talking to answered.

‘Well, that is part of the problem, sir. The ticket does read valid, but there is no name on it. It was presented by a Professor Summerfield, who was here recently. From the Phaestor Osiris expedition.’ He paused for the reply, turning the ticket over as he listened and squinting at a worn area of print on the reverse side. ‘That’s another odd thing, sir. The number is zero zero zero one.’

Benny watched in amazement as Elliniko’s jaw dropped. The laughter from the call-set seemed loud to her, and she was a desk away.

In other words, Braxiatel gave his brother the very first research ticket for his Collection. Incidentally, being in possession of this ticket gives one access to the VIP suites and the highest possible privileges on the Collection.

Both Braxiatel and the Doctor have a knee-jerk response of surprise when they realize that the other is directly involved in the affairs of the story.

On Braxiatel's part, it goes:

Braxiatel smiled and gestured for her to sit down again. ‘I’m afraid there’s really nothing much we can do.’

Benny sat down. He was right, but she felt no better for knowing that. ‘I suppose they’ll be okay,’ she said distantly and Braxiatel nodded sympathetically. ‘After all, the Doctor’s with them.’

The tea splashed into the saucer as Braxiatel turned sharply towards her. ‘What?’

While on the Doctor's part, it goes:

‘Well, it took me forever to work it out. I knew there was something wrong. Not with any particular document, you understand, but with all of them. As a collection. I think it was when I cracked that one that Braxiatel decided to tell me what was going on.’

‘Braxiatel?’ The Doctor’s chin left the umbrella and his demeanour changed from brooding consideration to alert intelligence. ‘You met Irving Braxiatel?’

‘Oh yes. Nice guy.’

And whatever the relationship was intended to be at that point, it seems to go back to very old times.

‘I realized you must know him when you used his research ticket. But it never occurred to me that he might actually be on Menaxus.’

‘Have you known him long?’

Braxiatel turned to her and smiled. The light from the setting sun lit his face, casting shadows across it which exposed an age and experience Benny had not noticed before. ‘For ever,’ he said.

Braxiatel shows utmost faith in the Doctor, completely certain that no matter the trouble, the Doctor will be able to handle it. ‘I’m sure the Doctor and his friends are quite safe.’ Braxiatel smiled. ‘Or at least as safe as they ever are.’ In a letter to the Doctor, he expresses this trust and requests that the Doctor help him modify his plans to more suit the Doctor's style of saving the universe.

But if you must interfere, and I know from experience that you must, then I hope you will consider my suggestions and advice. I am sure we are agreed about the ends, only the means – as ever – may be in dispute.

Despite our past differences, however, I hope you will understand my motives now even if you cannot condone the means. If it will help you rest easier, they were and probably still are the only means available to me.

If all goes well, we may meet again shortly. But if you choose not to wait, I will understand.

Good luck, my friend. May Time be good to you, and you to it.