Blind panic broke out at the blinding light.  The notion rather amused Jinsu, who sat down once she had got over her initial fear so that she could wait it out.  It took a good ten seconds, but vision gradually began to filter back in, and she could have sworn she saw Minseok having a good chuckle to himself about the various boys clinging to each other in fright.

The engines were still roaring around them.  Gradually, people became aware that they weren’t dying and began to calm down.

This was replaced by excitement when some of them got enough courage and interest to start looking around them again.

“The clock!” exclaimed Oh Sehun’s tall friend Kim Jongin, pointing towards the central clock.  “Look at the clock!”

Everybody turned towards the clock, even the technicians working at the computers, since it was their first proper trip on the Attayear too.

“Our watches, too!” another voice piped up.  Jinsu thought it sounded Kyungsoo, except that Kyungsoo never sounded that excited.  Heads dipped towards wrists, but since Jinsu didn’t yet have her own watch, she stayed looking at the central clock instead.  The hands were whizzing anti-clockwise around it, the second hand so quickly that it looked like a thin grey disk with a golden rim was spinning on the clockface.

Minseok hollered to get everybody’s attention and told them all to sit down, straddling a chair backwards to face them all once they were comfortable.

“What you’ve just experienced is what we call the Dive,” he explained, and everybody was instantly riveted, eager to find out more about the incredible machine they were in.  “The white light was the point at which we disappeared from the present – or the time we were in, whichever you want to call it.”

A hand went up.  “Does it actually take us ten seconds to vanish?  The light lasted a long time.”

Craning her neck, Jinsu could see that the questioner was Junmyeon’s friend who’d won third place with him.

Minseok held up a hand to show that he’d heard the question and then looked around.  “Who heard the sonic boom as the light became blinding?”

Several hands went up.

“Was that what the massive piyooo! sound thing was?” Lee Taemin called out.  “I thought something malfunctioned and that we were all going to die!”

There was a snort from somewhere in the crowd of boys and then Jo Minhwan spoke up, his sound scathing.  “It wasn’t nearly loud enough to be a sonic boom.  Not for a machine this size.  It would have deafened everybody on board.”

Minseok tilted his hand down to point at Minhwan.  “True.  I called it a sonic boom because it’s the easiest thing to compare it to.  It’s actually a temporal boom, so it’s much gentler.  Now, who heard the second boom that came five seconds after, when the light was brightest?”

There was a scoff from someone, and Jinsu recognised the next speaker as one of Minhwan’s friends, though she couldn’t for the life of her remember his name.  He had a very strong jawline, though, and his narrow eyes and low brow made him look very angry.

“What is this, school?” he demanded.

“I’m trying to teach you something,” Minseok told him dismissively.  “You have the honour of being the first people in the world to travel on a time machine and one day your grandkids will want you to tell them all about it, and then you’ll regret not taking advantage of learning everything you could at the time.”

“This is the first trip,” Minhwan agreed with his friend, doing a volt-face.  “You could just be making it all up as you go along.”

Minseok laughed.  It wasn’t as derisive as Minhwan’s tone had been, but it was enough to send shivers down Jinsu’s spine, and she couldn’t help edging back at the flinty quality that entered his gaze.

“Look, kid,” he said, “if you think that’s the case, you’re welcome to take my place and try to bullsh*t your way through navigating the centuries, because if I’m making it up as I go along, there’s no reason why any old ignoramus shouldn’t be doing this.  Wanna give it a go?”  He made to get up from his seat.

“I meant we have no idea of verifying if what you’re telling us is the truth.  You could be feeding us a pack of lies to tell our grandkids,” Minhwan threw back.

“He assumes he’ll have kids with that attitude, let alone grandkids?” muttered a voice from beside Jinsu.  “Wow.”

She turned to see that Yixing had moved and was sitting near her, a large green cloth on the floor in front of him that was littered with what looked like tiny cogs.  He was holding something round in his hand and focussing with a screwdriver as he deftly fastened the round object to another.  He looked so utterly engrossed in his work that Jinsu was a little surprised he was aware of what was going on around him.

Minseok seemed to think it wasn’t worth engaging Minhwan in any more conversation.  “Well, did you hear the second temporal boom?” he asked before moving on to the general group before Minhwan could reply.  “Did any of you?”

Only two hands went up – Kyungsoo’s and Baekhyun’s.

“It was much quieter,” Kyungsoo said eagerly.  Jinsu could see Baekhyun looking around for other people who might have heard, and when his eye fell on her and he saw neither of her hands were raised, he gave a smug smirk and settled back happily.  Jinsu guessed he was putting that as a point to his family over hers on the scoreboard.

“Baekhyun and I hypothesise the first was the point at which the machine gathered enough momentum one way or another to sit in a time stasis, so we were no longer continuing along the time spectrum with everybody else in present time – home time, whatever it is – and then the second one was when we actually actively started going back in time, which required less of an effort than slipping into the stasis or stopping it because most of the momentum was already there and it just needed a final nudge.”

There were several murmurs of interest from the others in the Attayear, and Kyungsoo lowered his hand, his sudden burst of confidence wearing off.

“You’re sixteen, right?” Minseok asked.  Jinsu wondered how he knew, but then figured that he’d probably heard about Baekhyun’s friends from Baekhyun, even if he’d never met them.  Kyungsoo nodded.  “Very impressive.”

Kyungsoo’s cheeks turned a little pink.

“And based on that extremely shrewd analysis, who can guess how long it took us to disappear from present time?” Minseok asked.

This time, it was Kim Wonsik who spoke up.  “It would have to be in less than a second, if we weren’t moving forward in time,” he said, “which would necessitate a time vacuum forming around the machine.”

“Exactly!”  Minseok beamed at him and turned back to Junmyeon.  “There you have it.”  He shifted, presumably for comfort.  “Now, I know that most