'Which was?' Gale asked, wishing Henshaw would hurry.
'The weapons those things were using. They weren't any more advanced than the best we had. Or that were in use by several other countries, for that matter. We contacted old Treadwell, here, and then we really started doing some digging into past experimental programs.'
'And that's how they started coming up with answers,' Indy picked up the explanations. 'They brought me into the picture to look over their shoulders. When they had what they judged were some solid leads, they pounded it into my head.
That's how I sometimes seemed to be so knowledgeable on the matter. It wasn't what I was figuring out. It was all memorizing what these people taught me, and we figured if I made public statements about the discs, it would simply be more bait added to the effect of the artifacts. It would start to appear as if I was behind stripping away the cover of this group.'
'We did some highspeed photography,' Treadwell added. 'That was an enormous help. It was touchandgo for a while because we had to stumble across an opportunity to film the discs. We used still pictures and highspeed films.
Would you believe that out of some sixty cameras we set up with the Americans, only two produced results?'
'And—' Gale let the query hang.
'Hydrocarbons,' Treadwell said with triumph. 'That was the clue! I felt like Sherlock Holmes. You see, there is an exhaust trail behind those infernal devices.
The films, and those pictures you people took while you were waltzing across the Atlantic, proved it. Remember that huge ship you encountered at sea?'
'Hard to forget,' Gale murmured.
'Your photographs confirmed what we'd suspected. That monster mother airship, easily fifteen hundred feet from one end to the other, could hardly be concealed in Europe. Population density and all that. The key was that any kind of aerial vessel of that size needs servicing, and a lot of it. Refueling, supply replenishment, engine tuneup, liftinggas refills. That ship took care of that. Those side booms extending out on each flank? When the dirigible came down to the deck of that vessel, a mooring mast and the booms came up to snug down the big zep—well, I see by your expression you've already figured it out yourself.'
'Wait; wait!' Gale broke in. 'All right, you have this evidence of hydrocarbons and all, but I still don't know what that told you!'
'That Frenchman I mentioned?' Henshaw said. 'That Coanda fellow. I recalled he told me that if you designed an engine that worked like a blowtorch—suck in huge i gobs of air at one end and set it aflame so you're compressing it, then blast it out the other end—why, you could power just about anything with it. An aircraft, or that great dirigible.
An engine like that would even fit neatly into a disc shape.'
'No propellers?' Gale asked, amazed.
'Oh, there's some kind of propeller, but it's inside the engine,' Henshaw answered. 'We had our people test different fuels and the chemistry crowd said we were dealing with the exhaust from superrefined kerosene.'
'Which blew away the theory that we were dealing with meanspirited ugly little green fellows from Mars,'
Treadwell added.
'And which let us force the hand of this group,' Indy said.
'And how, Jones, did that happen?' Pencraft said testily.
'Well, sir, for starters,' Jones spoke gently to his aged friend, 'those artifacts are paying off in a way I hoped they would. Whoever is running this group, or at least is
one of the top people, made a decision that the cube and the pyramids were fakes. But he could do that only by coming to a dead end with the cuneiform inscriptions. They were nonsense, of course, but I made certain they appeared to be real. You, of all people, Doctor, know how much time must go into working with unknown cuneiform.
And whoever was examining those things came to a conclusion much too fast for your ordinary researcher.'
'Which means,' Gale said suddenly, 'he has archeology experience! Of course!'
'That,' Indy went on, 'and also deciding that as unknown as was the metal that Treadwell had made in the secret metallurgical lab, it could be fashioned by any really competent people in the metalworking business. In short, they knew too much in too short a time.'
'Enter one Filipo Castilano,' Treadwell added. 'Do you recall, or perhaps you never had the chance to notice, the stories that made all the papers about that place in France? That some biblical historians are claiming was the final resting place of Christ?'
'Do you mean the little French town of Arques?' Pencroft asked.
'Yes. We had detailed maps of the area, of course,' Treadwell said, 'from Jacques Nungesser. Jacques also placed special agents through the countryside.
Farmers, tradesmen, that sort of thing, to keep watch on and record the movement of everything that went into or came out of two places in particular.
RennesleChateau and the Chateau of Blanchefort.'
Pencroft grumbled his distaste. 'That is all nonsense,' he stated emphatically.
'That story has been cropping up for years. It's in the same league, you should know, with the tales of Christ living out many of his years right here in England.
Having a merry old time with the ghost of King Arthur, or perhaps Arthur in person, with Merlin entertaining the crowd. It's about as reliable as the tales of a Christlike figure appearing among the Maya and the Aztecs, and materializing before amazed people in China. Why is all this even brought up in this matter?'
Treadwell remained patient and understanding. 'Because there has been major construction work on
