I jump in, “Let me guess, the scientist who built the time machine was financed by a group who lost a war, at sometime in the past, and wanted to change history by sending an agent back to let their side win the war.”

The alien doesn't respond, but looks at me for a bit.  The alien then says, “I'm not permitted to answer your question.  However, the scientist was financed and did build the time machine that you used.  The illegal machine was discovered and the scientist was prevented from using the machine.”

“Obviously, your scientists can detect the use of a time machine.  You then tracked down what you describe as the illegal time machine.”

The alien snaps, “What you have said is merely a guess on your part.”

“Not really, the situation is actually rather obvious.  If you look at the patterns of what has happened, there's really only one correct conclusion that you can arrive at.”

The alien asks me, “Describe the path of your reasoning.”

“I don't give up information, unless I get information in return.”

The alien snarls, “You try to play games with my civilization, a civilization that could wipe all life from your planet?”

“A time machine is illegal in your civilization, but wiping a planet clear of life, including sentient life is permitted, do you really expect me to believe that?”

The alien pauses for just an instant and they asks, “What is your position in this planet Earth of yours?”

“I work at a job.  I'm also the only one in the universe who has really traveled in time, for more than a few seconds at most.  I am an important person, here on Earth.  I am even more important to your civilization.”

The alien snaps, “Oh, why are you important to my civilization?”

“In the history of Earth, the nations that more or less ruled the Earth sent ships across the ocean, basically to find the source of certain spices that had to travel very long distance overland and hence commanded a very high price.  The money cost of equipping the ships was high and the cost in human life was also high.  However, the rewards dictated at least an attempt.  Your civilization doubtless had to spend a lot of money and even risk the lives of you and the crew of your space craft.  You didn't come all the way to Earth because you were worried that we might change the history of Earth.”  (The last sentence is a clever lie and I wait to see if the alien detects that.)

The alien snaps, “What makes you so sure that we came by space craft?”

“Again, the answer is obvious, but you don't get my answer until you offer something of at least equal value in return.”

The alien considers what I have just said.  He then asks, “What is it that you want in return?  Perhaps the science of the space craft engines that you have convinced yourself that we have?”

“Of course not.  How about some computer circuit secrets or metallurgical secrets, small things that will be valuable to my nation, but not great leaps in our current science.”

The alien appears to consider what I have said.  The alien then says, “I need to talk to some of your science people to see what we have to offer that might be of equal value.”

“That's fine, I'm not going anywhere, I don't have a space craft.”

The meeting breaks up.

I get marched into another meeting with several self important government people.  They start to chew on me.  I break in, “I have gotten some small scientific advance from the aliens, without giving up anything.  Could you have done as well?”

The most self important guy snaps, “We run this operation, not you.”

I say, “Okay, you tell the alien about time travel, I won't say a word.”

The meeting then breaks down into a lot of petty squabbling.  Eventually, one of the people gets up and says, “Mr. Jason Williams has done well, so far.  He will continue to talk with the alien, until he does less well.”

(Apparently, the guy is a person of importance.)  I'm then told that what the alien offered is of value and that I should cooperate with the alien.  I'm marched back into a second meeting with the alien.

The alien tells me, “Your people are satisfied with what I offered.  Now, tell me why you are so sure that we came by space craft.”

“You either came by space craft or by some other transportation method.  Not so long ago, we had trains, mobil units that ran on metal tracks.  Where the tracks went, there was an important place.  Until just recently, Earth was not an important place.  Thus, your other method of transportation would not have been connected to Earth.  Hence, you came by space craft.”

The alien says, “Yes, that is clever reasoning.  Of course, we had to be able to detect the use of a time machine, in order to track the time machine to planet Earth.  Your people then told you of a space craft.”

“My people told me nothing.  I did manage to reason why a space craft was involved.”

The alien pauses for a bit.  “I have described another little scientific advance to your scientific people.  It should be worth your description of your reasoning.”

The voice of the same man who shut off the politicians says, “Yes, we'll make that trade.”

“You had a person, financed by a group.  The person then built an illegal time machine.  You detected the testing of the time machine and sent in enforcement people.  There was likely a battle.  During the battle the group who financed the time machine managed to escape, taking along the illegal machine.  The enforcement people were probably unwilling to risk destruction of the machine, because such destruction might kill a lot of people, including the enforcement people.  Then the group managed to take the machine away, in a space craft.  The space craft crashed, here on Earth.  That's how we got the time machine.”

The alien seems to evaluate what has happened.  The alien then says, “Your people have agreed to let us examine you.  Does that scare you?”

“I'm probably the only real time traveler in the universe.  You are not going to harm me.  I'm too valuable.”  (The only reason that the aliens want to evaluate me in depth, is that they have a mission for me.  I'm gonna have to do it, but I'm gonna get paid for it, well paid.)

The alien then leads me off, across a barren landscape to what appears to be an aircraft hanger.

We go in and I see several more aliens.  I'm marched to some kind of machine and hooked up to what must be sensors.  One of the aliens then asks me (via the first alien,) “Describe exactly what happened during your time travel.”