‘I do,’ Ace conceded. ‘30 years ago, Professor, when you started all this on the Wraith world … You told me then that I could be an emissary. Did you never think I could be up to that challenge?’

‘For all my planning, and plotting, and rigging the odds, you were always there, beside me. So strongly there, I never stopped to truly imagine your future … What you could really be.’ The Doctor smiled. ‘But I see you now. I see you so clearly. I really have changed, Ace. Just as you have.’

Ace found strength to smile. ‘Older and wiser?’

‘Nah.’ The Doctor shook her head. ‘Older and brilliant.’

CODA

‘Lights.’

The dim emergency lighting in the deserted batcave came on as Will Buckland stepped through the door. He saw at once that nothing had changed from the last time he had been here.

He had gone through the same routine every week for over a month now, always hoping to find some sign of Dorothy or the Doctor, always disappointed.

He’d stopped telling Sam where he was going now. He was sure she knew in any case, and it wasn’t like he had anything better to do. She had taken his old job now, while he had been quietly let go amid talk of mental breakdown and paranoid delusions that had led to him being granted indefinite garden leave. He knew his career was finished.

But he also knew his business here was not. If she were able, Dorothy would find some way to get in touch with him. Or the Doctor would. Surely there had to be hope?

He made a slow circuit of the workshop, listlessly rearranging items on the shelves, checking that the equipment was still working. Without the Squidget as a control, the alien power source that ran the batcave was silent and cold. It was only because he topped up the petrol generators outside each week that he still had light and heat.

Satisfied that everything was still in order, he was about to turn off the lights and leave when there was a knock at the door.

‘Dorothy?’

Not daring to believe it, Will hurried to the door and flung it open. Sanaul was standing there, a silver box in his arms, a large white envelope taped to its lid.

The envelope was marked with a single word: ‘WILL’.

Sanaul silently handed over the box, then turned and limped back to his Range Rover. The old man had recovered well from his ordeal – after seeing the remains of Dorothy’s flat, Will had been amazed that anyone had walked away from it. A pair of green eyes in a black furry face suddenly appeared at the passenger window, and Will smiled. It wasn’t only Sanaul who’d survived.

Will closed the door and set down the box on the workbench.

For a few moments he stared at the closed metal lid. Then he opened it up.