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16:57 (UTC+8)
Anna and Simon were fleeing down a long radial corridor when they felt the missile's engines start up, shaking the floor beneath them. Anna had been looking back over her shoulder every few paces, convinced each time that she would see a horde of mechanical nightmares scuttling after them in the dim light, and each time stumbling because her balance was off with her arm in the sling - but there had never been sign of pursuit.
'Earthquake!' Simon yelped, steadying himself on the wall as he loped along.
Anna threw him a scathing look.
'What? Oh.'
She glanced behind them again. Still nothing.
'The reactor chamber walls will stop the blast, right?' he asked.
'Probably,' Anna gasped, rapidly running out of breath. 'But I guess it depends how much mass they decide to pump into the reactor.' She flashed him a weary smile. 'But on the bright side, the more they pump in, the sooner the bomb will reach the loading chamber.'
'And you are sure that explosion won't kill us?'
'The walls were designed to handle a rogue evaporation event of that magnitude,' she said, veering off and plunging down a corridor perpendicular to them.
Simon followed, and as they reached the door to a stairwell pulled it open for her.
'What's USSIME?' he asked, reading the sign on the wall as they entered.
'Ultra Small Scale Investigations of Matter and Energy,' she replied, starting up the first flight of stairs. 'It's one of the project areas I worked with. They have a building above us.'
Simon leaned out over the stair rail to look upwards. 'Why did they have to build it so high up?' he asked.
'We're a long way down,' she said, unsure if he was trying to make a joke, or whether the heat, stress or fear was getting to him a little. Maybe all three, she decided.
They clambered upwards, taking flight after flight in the gloomy emergency lighting, and Anna's calves and thighs began to ache more with every stride. She was just wishing she had spent more time on the step-machine in the gym when the rumbling around them changed pitch, and she and Simon paused to listen.
A moment later the upper reaches of the stairwell were blotted out by smoke and boiling fire, billowing down towards them with a reverberating roar.
'Run!' Simon yelled.
Anna spun on her heel, jumped back down the last few steps she had climbed and yanked open the door at the bottom of the flight. She dove into the corridor beyond and lurched right, then left as a terrific boom sounded and she heard the stairwell door disintegrate behind her.
She ducked into an open restroom as heat and debris billowed past the doorway, and the emergency lights went out, plunging her into darkness.
'Simon?' she called, as the noise grew, the walls shook around her and the air thickened with the soaring temperature. 'Simon!'
But no answer came.