Commander Wilson stiffened as the new recruits ('new' being a relative statement) began leaking into the room. He stood in front of them all at a podium, like a college professor lecturing to a class. And the lesson for today was...
"Time-travel," he said, "is a very difficult thing to comprehend. As is time itself. It's understandable that you will have a lot of questions, but believe me, somebody could spend an eternity asking those questions and never find a satisfying answer. But you are no philosophers. It's not your jobs to answer those questions. You are... social workers. You correct time, guide it, not understand it."
Wilson glanced around the large room. I'm rambling again... Oh, way to make a first impression, Wilson
"You are all here, because according to the future field reports, you are the best and the brightest of all our new recruits, and of humanity. But remember, the future is always changing; just because we say you survive to see tomorrow, doesn't mean you will an hour later. Your actions have consequences that you cannot begin to comprehend - what you do effects your future, which effects your missions, which effects us. Follow protocol at all times, or you will be more trouble to us than you are worth."
Commander Wilson realised he was assuming a grave tone. He tried to lighten the mood.
"So, all you people who ever wanted to meet Elvis - you've got your chance right here."
He cringed as soon as he'd said. Humour... not one of my strong points.
"Now," he continued quickly, before the cadets had a chance to snicker at him. "You will be divided into five squads. Each squad will be assigned to a different mission. These are training missions - they are important, but will most likely not involve any combat situations. At least... so long as everything goes as planned..." a grim expression spread over Wilson's face "... but remember - this is a field operation, not a simulation. The dangers are very real. If you screw up, there can and will be catastrophic effects. Please follow the directions of your squad leader at all times. It is now time to make your choice..."
Wilson flicked a switch, and a number of choices flashed up on each cadet's metal wristband - their link to the Keeper mainframe.
"You see before you a list of five missions, each one identified by the destination and main objective. In descending order, they are assigned to the respective squads: Alpha, Beta, Gamma, Delta and Epsil. Make your choice by simply tapping the screen. You will be Phaseshifted shortly."