Over the spreading cacophony of alarms, Eddie heard a shout behind them. ‘We’ll try it.’ They set off. ‘So this whole place was built for Eleanor to sit out the apocalypse? Why’s it so huge?’

‘She was planning to preserve all human knowledge down here – at least, the parts she thought were worth keeping. So it’s got archives, tools, weapons—’

‘Weapons? Why didn’t you bloody say so? These are all storerooms!’ The doors they passed bore signs, but in her hurry, Nina hadn’t read them. Eddie glanced at the next as he ran past. ‘Seeds – not much use!’

‘Maybe these?’ she suggested. There were three more doors ahead before the passage made a right turn.

But the labels told them the rooms’ contents were no more use than the seed bank. They rounded the corner – only to stop in dismay. ‘Shit!’ said Eddie. It was a dead end, a last door in the far wall thirty feet away. ‘We’ll never get back to that junction before they catch up.’

‘Eddie, wait!’ Nina cried, hurrying onwards. ‘You want weapons? Here you are!’

The door’s sign read Arsenal. ‘Hope it’s not just because Ellie supports the Gunners,’ he said, joining her. He tried the door, and was surprised when it opened. ‘What, they don’t even lock their fucking gun room?’

‘Eleanor meant for everyone down here to be asleep,’ Nina pointed out as they entered. ‘But they only recovered one sarcophagus. And maybe she planned to lock up properly before entering stasis.’

‘Still slack. Works for us, though!’ The walls were lined with hundreds of metal drawers. Eddie pulled one open at random. ‘All right!’ he said, taking out an M16, the US Army’s standard infantry weapon. ‘Now just need some ammo . . .’

He opened more drawers nearby, but found only guns, all lacking magazines and ammunition. ‘This is no bloody good!’

Nina joined in. ‘Guns, guns, guns – but no frickin’ bullets!’ She reached for another handle, then paused: bullets would be stored in large quantities, a heavy load, so most likely were in the larger drawers at floor level. She tried one, and was relieved to find it full of neatly packed cardboard boxes. ‘Got them!’

Eddie shook his head. ‘They’re nine mil – I need five-point-five-six. And a mag.’ He opened more drawers himself. ‘Nine mil, nine mil, fifty cal . . .’

A noise over the alarms: running footsteps. Getting louder.

‘Someone’s coming!’ Nina cried, trying more drawers.

More nine-millimetre ammunition, shotgun cartridges—

‘Yes!’ Military-issue cases stencilled 5.56 mm. She pulled one open and withdrew a card sleeve holding thirty gleaming rounds. ‘Got the bullets!’

‘Magazine?’

‘Oh, God damn it!’ She hurriedly gave him the bullets before yanking open more drawers. ‘I can’t find any!’

They were out of time. Their pursuer rounded the corner, pounding towards the arsenal—