The first time it happens, it's a shock. It hits you like a stack of phonebooks dropped from the eighth storey of a downtown highrise, presses you down on the sidewalk and just as you wish the weight would be lifted, it is. Now you're stretching, out and out, beyond the limits of your own skeleton. Your skin pulls at you, begging to be left behind as your head rockets skyward, your arms wrapping themselves uncontrollably around the horizon. Then it stops: you're floating now. For the first time in what seems like forever, you breathe again. Then: touchdown.

Uncerimoniously, Felix dropped three feet onto the hard stone floor, rolled onto his back and lay, panting, "I wasn't prepared for that," he spluttered through hoarse, deep breaths.

Mac, his friend and mentor, handed him a towel: "you get used to it," he said simply, "you'll be OK again in a couple of hours. At least you didn't break anything - my first go at it, I came out of it with an arm broken in three places."

Felix said nothing. He buried his face in the gratefully accepted towel and tried to regain control over his breathing. He'd heard that story before - about Mac breaking his arm - but he'd also heard that Mac didn't even notice until hours later when he peeled off his jumpsuit. Mac was a hard man, in a different league to Felix himself.

"Gimme the bracelet, I need to hand it back in."

Through hazy vision, Felix unclipped the thick bracelet from his arm and handed it up to the looming Mac. He rubbed at his wrist where the device had been secured, feeling a twinge of pain as his fingers lingered over the two mosquito-like puncture marks that had bound his nervous system to the will of the Machine.

"Hey," Mac grinned, nudging Felix with the toe of his boot, "take a look up there," he pointed out a distant figure in a glass box suspended at the ceiling of the giant warehouse they currently occupied. Felix squinted, but couldn't make out any features.

"So? It's just a guy, watching us. Maybe another recruit on orientation?"

Mac stifled a laugh, "that's you, dummy. Today's Thursday - that's your orientation. What part of time travel do you not understand?"

It dawned on Felix that maybe he hadn't quite understood what he'd gotten himself into.