His companions always left him; he was used to that. Their lives were lived at a different tempo from his, and he understood it. Each was so short and so intense, and each had needs that he probably could never really comprehend. But there was always some sort of closure when they left him, a feeling that their time with him was done, that they had learnt what they must, even that their lives thereafter would be helped by the time they had spent with him.

Not so Sam. Their journeys were not yet finished. Their purpose was not yet accomplished, whatever that purpose was. The Doctor knew that he was rationalising his own insecurities, but he was sure of this. He and Sam were not yet finished with each other. He couldn’t simply let her go.

‘Emotion,’ he said loudly. ‘That’s the trouble. I can pretend I’m not involved, but it’s a lie.’

Wonderful. Now he was talking to himself. Was he that desperate for company?

Yes. He was.

‘This isn’t about me,’ he said. ‘It’s about her. She’s probably in trouble, in desperate need of me.’ He reached out to touch one of the roundels in the corridor wall. ‘Come on, old girl. We can find her. I know we can.’ He let his hand fall. Who was he trying to fool? The TARDIS knew his every thought before he did. And he knew what a sham he was. He hurt, and he needed companionship. Had Sam taken a rational decision to walk away from him, to leave the TARDIS and their travels for ever? What had happened to her down on Hirath?

Well, there was nobody else around to feel sorry for him.

He hurried on his way to the main console room. Inactivity chafed his soul. He had to do something, anything, to try to find Sam. If she was fine, then he could walk away and leave her if that was what she wished. If she was in trouble…

He hated himself for hoping she was in trouble.

Stars whirled overhead as he strode into the console room. Usually he could enjoy the view, but now he was too bothered. He hurt. He hadn’t felt this alone since his decision to leave Gallifrey. That had been hard enough, and even harder when he’d decided to take Susan with him. He couldn’t leave her behind to be brainwashed and regimented in the thought patterns of the rulers of his homeworld. But the decision to flee had been so hard…

Why was he thinking of that now? It had absolutely nothing to do with Sam, or his recent ordeal. Was his mind starting to wander? Was he so reliant on having someone around to admire him?

He collapsed into his chair and poured himself a cup of Earl Grey. He sipped at it, but tasted nothing but bitterness. He replaced the cup and glared at it. Was there no relief for him anywhere? He picked up the book he’d been reading, and was surprised to discover it was Songs of Innocence, a first edition, personally inscribed by William Blake. He couldn’t remember reading it, but it was open at ‘The Divine Image’. He read:

‘For Mercy has a human heart,

Pity, a human face:

And Love, the human form divine,

And Peace, the human dress.’

The Doctor sighed. ‘I think you got it wrong, William,’ he murmured. ‘I have human dress, but no peace.’ Blake had used a child as the symbol of innocence in those poems, and it had been far, far too long since he was either a child or innocent. Perhaps that was what attracted him to humans so much – their almost endless capacity for being children, and being so innocent even in a hostile universe. He strove himself for a lack of guile, but it was so very hard to achieve.

‘What have I done?’ he asked the room at large. ‘I’ve run from my people, and hidden myself. I’ve fought for what I believe is right. Sometimes I’ve even won. But what has it gained me? What do I have to show for it? I’m sitting here alone, arguing with myself! And, worse, I’m losing!’

Wasn’t the first sign of dementia talking to oneself? Or was it answering oneself?

He jumped to his feet and crossed to the console. ‘We have to find her,’ he informed the empty console room. ‘She can’t have gone far. I have to know. Where is she?’ He slammed his fist down on the panel as if chastising the TARDIS itself. ‘Tell me!’

There was no reply. The TARDIS was probably sulking.

‘Earth,’ the Doctor decided. ‘Maybe she’ll have gone home.’ He shrugged. It was a better place than most to start his search. Besides, he had exactly three options: forget about her, look for her, or sit and mope. He’d brought Sam out among the stars, and shown her wonders and terrors she’d never dreamed about before. He couldn’t abandon her now.

While he wasn’t exactly convinced he was doing the right thing, he was at least doing something. In Thannos time it had been 3177, so allowing for that… His hands flickered over the controls, setting the destination co‐ordinates for London, in the year –

A light pulsed on the console, and the Doctor stared at it. The telepathic circuits… Sam. Had she –?

Then a blast sent him tumbling across the room, his mind a searing blaze of pain.

Agony. Despair. Death.

The Doctor managed to crawl to his hands and knees, his mind scorched by the strong telepathic message that had broken past all of his normal safeguards. His limbs shook, and he couldn’t focus his mind on anything but the appalling – the terror –

The end of everything. Nothingness. Pain. Obliteration.

And: Kill!

He was aware that he was whining slightly as he staggered to his feet and lurched back to the console. He slammed his hand down on the telepathic contact, cutting off the message, and freeing his mind again from its dreadful grip.

He breathed deeply, leaning on the panel until the shaking in his body had ceased. The message had been so strong it had threatened to overwhelm him. But he had recognised it in the few seconds it had lasted.

‘Susan…’ he whispered. Was it merely a coincidence that he’d been thinking of her only minutes before? Or was coincidence just another word for causation?

What had happened to her? What or who had she been wanting to kill? That wasn’t the Susan he’d –

Then he stopped himself. What she was like now, he had no idea. A twinge of guilt needled his mind as he realised that he’d hardly thought of her in ages, let alone visited her as he had promised so glibly. If it hadn’t been for Rassilon’s Game, he’d never have seen her at all in all these hundreds of years. And even then, he’d barely talked to her.

What was behind this message? He was starting to think coherently again, though his head still throbbed. A mental blast like that, amplified through the telepathic circuits, could do a great deal of damage to any Time Lord close to the source. He checked the space‐time co‐ordinates and discovered something very strange. First of all, the mental blast had come via the telepathic circuits of another TARDIS. Which didn’t make any sense, because Susan certainly didn’t have access to one. Did she?

And second, it had come from a world other than Earth, and at a distant time.

Somehow, obviously, she must have come into contact with another TARDIS. Or was it his, but from some other incarnation? It wasn’t one of his past selves, of course: he’d have recalled such a meeting.

Which didn’t, of course, rule out either his own future self or a future regeneration. He checked the records, though, and discovered that the carrier wave didn’t match his own TARDIS. So she had somehow made contact with another Time Lord, and used his or her ship to get off Earth, either voluntarily or as a captive. The latter was only too plausible, considering only renegades made a habit of picking up people from one world and transporting them to another.

Like himself.

But, then, there was the content of her message, racked by pain and anguish that he could hardly understand himself. What could have driven her to this? And there had been that sensation that death was hovering close beside her. Susan hadn’t been fearing impending death – she was facing it. Not with doubt, but with certainty. Was her message, then, aimed at him – a cry for help?