The only other book with interaction between Brax and the Doctor is Theatre of War.

He proceeded into the second half of the breakfast room, past the new partition with the brick-effect wallpaper, still searching for his book.

He found it in the hands of a serious man in a summer suit, his spectacles balanced on the end of his nose, much as his leather-booted feet were balanced by the milk jug on the table.

The Doctor raised an eyebrow. ‘Good morning, Brax.’

Irving Braxiatel lowered the book imperiously, a slight smile on his lips. ‘You’re trying to learn cricket from Neville Cardus, Thete? One might as well study P.G. Wodehouse for advice on etiquette.’

‘I borrowed a Know The Game from the library as well.’ The Doctor plucked the book from the tall academic’s hands. ‘You’ll play, of course?’

‘Hah! You remembered!’ Braxiatel swung his legs off the table. ‘Of course. Your team will have its work cut out otherwise. Does your TARDIS have a selection of whites? Yes, I’m sure it does. Interesting experiment in social engineering you’re pursuing here, Thete. Terribly dangerous.’

The Doctor looked at him seriously. ‘But terribly life affirming. Now, we’d better get you into the nets.’

And then at the actual cricket game:

Braxiatel was sitting quietly on a bench, studying the scene with his penetrating gaze. The Doctor hoped that he wasn’t going to play this game ironically, as he sometimes did. He was so good, in intellectual as well as sporting pursuits, that he often pretended not to be, to give himself a rest. No ambition, that one, or no sense of adventure.

Which is essentially the end of it for that one. Aside from the actual cricket-playing.