very dangerous.
Doc took the chagrined airport attendant with him in the army pursuit plane back to Washington.
Ham and the others were waiting when Doc arrived, after restoring the pursuit plane to the army field.
'Have any trouble getting our papers up?' Doc asked.
Ham tightened his mobile, orator's mouth. 'I did have a little trouble, Doc. It was strange, too. The Hidalgo consul seemed very reluctant to 0. K. our papers. At first he wasn't going to do it. In fact, I had to have our own secretary of state make some things very clear to Mr. Consul before he gave us the official high sign.'
'What's your guess, Ham?' Doc asked. 'Was the official directly interested in keeping us out of Hidalgo, or had some one paid him money to make it tough for us?'
'He was paid!' Ham smiled tightly. 'He gave himself away when I accused him of accepting money to refuse his 0. K. on our papers. But I was not able to learn who had put the cash on the line.'
'Somebody!' Renny rumbled, his puritanical face very long. 'Somebody is taking a lot of trouble to keep us out of Hidalgo! Now, I wonder why?'
'I have a hunch!' Ham declared. 'Doc's mysterious heritage must be of fabulous value. Men are not killed and diplomatic agents bribed without good reasons. That concession of several hundred square miles of mountainous territory in Hidalgo is the explanation, of course. Some one is trying to keep us away from it!'
'Does anybody know what they raise down in that neck of the woods?' Monk inquired.
Long Tom hazarded a couple of guesses, 'Bananas, chicle for making chewing gum — '
'No plantations in the region Doc seems to own,' Johnny, the geologist, put in sharply. 'I soaked up all I could find on the precise region. And you'd be surprised how little it was!'
'You mean there was not much information available about it?' Ham prompted.
'You said it! To be exact, the whole region is unexplored!'
'Unexplored!'
'Oh, the district is filled with mountains on most maps,' Johnny explained. 'But on the really accurate charts the truth comes out. There's a considerable stretch of country no white men have penetrated. And Doc's strange heritage is located slap-dab in the middle of it!'
'So we gotta play Columbus!' Monk snorted.
'You'll think Columbus's trip across the briny was a pipe when you see this Hidalgo country!' Johnny informed him. 'That region is unexplored for only one reason — white men can't get into it!'
Doc had been standing by during the exchange of words. But now his calm, powerful voice commanded quick attention.
'Is there any reason we can't be on our way?' he asked dryly.
They took off at once in the monster, low-wing speed plane. But before their departure, Doc telephoned long distance to Miami, Florida, where he got in touch with an airplane-supplies concern. He ordered pontoons for his plane, after determining the company kept them in stock.
The approximately nine-hundred-mile flight to Miami they made in something more than five hours, thanks to the tremendous cruising speed of Doc's superplane.
Working swiftly, with lifting cranes and tools and mechanics supplied by the plane-parts concern, they installed the pontoons before darkness flung its pall over the lower end of Florida.
Doc taxied the low-wing speed ship out over Biscayne Bay a short distance, making sure the pontoons were seaworthy. Back at the seaplane base he took on fuel and oil from a seagoing filling station built on a barge.
To Cuba was not quite another three hundred miles. They were circling over Havana before the night was many hours old. Another landing for fuel, and off again.
Doc flew. He was tireless. Renny, huge and elephantine, but without equal when it came to angles and maps and navigation, checked their course periodically. Between times he slept.
Long Tom, Johnny, Monk, and Ham were sleeping as soundly among the boxed supplies as they would have in sumptuous hotel beds. A faint grin was on every slumbering face. This was the sort of thing they considered real living. Action! Adventure!
Across the Caribbean to Belize, their destination on the Central American mainland, was somewhat over five hundred miles. It was an all-water hop.
To avoid a head wind for a while, Doc flew quite near the sea, low enough that at times he sighted barracudas and sharks. There was an island or two, flat, white beaches bared to the lambent glory of a tropical moon that was like a huge disk of rich platinum.
So stunningly beautiful was the southern sea that he awoke the others to observe the play of phosphorescent fire and the manner in which the waves creamed in the moonlight, or were blown into faintly jeweled spindrift.
They thundered across Ambergris Cay at a thousand feet, and in no time at all were swinging wide over the flat, narrow streets of Belize.
Chapter 8. PERSISTENT FOES
The sun was up, blazing with a wild revelry. Away inland, the jungle was lost in a horizon infinitely blue.
Doc slanted the big plane down and patted the pontoons against the small waves. Spray fanned up and roared against the idling propellers. He taxied in toward the mud beach.
Renny stretched, yawned. The yawn gave his extremely puritanical face a ludicrous aspect.
'I believe that in the old pirate days they actually built a foundation for part of this town out of rum bottles,' Renny offered. 'Ain't that right, Johnny?'
'I believe so,' Johnny corroborated from his wealth of historical lore. Plink!
The sound was exactly like a boy shooting at a tin can with a small air rifle.
Plink! It came again.
Then — bur-r-r-rip! One long roar!
'Well, for — ' Monk swallowed the rest and sat down heavily as Doc slammed the engine throttles wide open.
Engines thundering, props scooping up water and turning it into a great funnel of mist behind the tail, the plane lunged ahead — straight for the mud beach.
'What happened?' demanded Ham.
'Machine gun putting bullets through our floats!' Doc said in a low voice. 'Watch the shore! See if you can get a glimpse of whoever it was!'
'For the love of mud!' muttered Monk. 'Ain't we never gonna get that red-fingered guy out of our hair?'
'No doubt he radioed ahead to some one he knows here!' Doc offered.
Distinctly audible over the bawl of the motors came two more metallic plinks. then a series. The unseen marksman was doing his best to perforate the pontoons and sink the craft.
All five of Doc's men were staring through the cabin windows, seeking trace of the one who was shooting.
Abruptly bullets began to whiz through the plane fuselage itself. Renny clapped a hand to his monster left arm. But the wound was no more than a shallow scrape. Another blob of lead wrought minor havoc in the box that held Long Tom's electrical equipment.
It was Doc who saw the sniper ahead of all the others, thanks to an eye of matchless keenness.
'Over behind that fallen palm!' he said.
Then the rest perceived. The sharpshooter's weapon projected over the bole of a fallen royal palm that was like a pillar of dull silver.
Rifles leaped magically into the hands of Doc's five men. A whistling salvo of lead pelted the palm log, preventing the sniper from releasing further shots.
