‘Let’s not think about graves right now.’ Yaz began to fiddle with her hands. She felt useless, surplus to requirements. But I can still think, she told herself. ‘Doctor, you said what the Wraiths used this place for. But the new owner is settling for sending some random people clear across the universe. Why?’ Yaz shook her head. ‘What’s so special about them?’

‘What’s so special about anyone? Ask the people that love them.’ The Doctor frowned. ‘Although, I don’t suppose that a lot of those people felt that anyone did love them; that’s what made them easy pickings.’

‘Only they’re not that easy, are they?’ Yaz countered. ‘The new owners here could’ve sent them through space in one big hit, like they did with Ace in ’87. Instead they’re using their stations like runners passing the baton in the longest relay race in the universe.’

‘That’s true. You’d think they’d pick a planet closer. So presumably, they can’t.’ The Doctor gasped suddenly. ‘Yeah, think about it. What if you’re under scrutiny from someone really big and powerful – so you have to move cautiously. No drawing attention to yourself. No big energy emissions that risk ructions in local space-time. You play safe and sneak what you need on a trail that’s next to impossible to follow for all but the most determined detectives, halfway across the universe …’

Squidget chirruped loudly, and Yaz jumped. ‘Has he done it?’

‘He’s done it.’ The Doctor looked up as the station shuddered again, and a deeper, louder groan rose up from around them. ‘He’s really done it. Squidge has triggered a ray phase shift!’ She waved the sonic around Squidget, studied it, and then bit her lip. ‘There’s gonna be fireworks. Ace, get back to the TARDIS.’

‘Ace?’ Yaz felt herself frost over. ‘You want fireworks, call me by her name again—’

‘Yaz! Go!’ The Doctor was wide-eyed with horror. ‘We’ve got 30 seconds till break-up.’

‘What?’ Yaz grabbed the Doctor’s arm. ‘Come on.’

‘No!’ The Doctor shook her free. ‘I have to find the next station in the sequence. Still got 22 seconds. Go!’

‘I’m not leaving you out here,’ Yaz insisted.

‘I need you to!’ the Doctor told her, squeezing Squidget tighter. ‘Go into the TARDIS and throw the big green lever on the panel furthest from the doors.’

‘What’ll that do?’

‘Something really important. Something vital. Go!’

Yaz scowled as she turned and ran back to the police box in the now-regenerated data store. But the walls were starting to blur, the shake in the floor was building like a wave. How many seconds were left to them now – 13? Fewer?

Diving into the TARDIS, Yaz ran to the far side of the console just as she’d been told.

There was no green lever.

‘No way,’ Yaz breathed.