He certainly did not delay when school was dismissed. Leaving his bicycle where it was, he set out rapidly on foot toward the south across the gardens. He had a double reason for leaving the machine: not only would it be useless in his present project as he visualized it, but its presence would make his friends assume he would return shortly, so that they would be less likely to follow him.
Threading his way along the paths between garden patches until several houses hid him from the school, Bob began to work his way eastward. He was seen, of course- there were few people on the island who didn't know all the other inhabitants; but the ones to whom the boy nodded greeting as he passed were merely casual acquaintances, and there was no fear of their following him or becoming interested in his activities. Twenty minutes after leaving the school he was a mile from it and fairly close to the other shore, almost directly south of the dock. At this point he turned northeast, along the short leg of the island, and quickly put the rising ground of the ridge between himself and most of the houses. The unused ground on this side had not grown up into jungle quite so badly as the other leg; the brush was fairly heavy, but there were no trees. This section was narrow, and his original course would have carried him eventually into the fields of what the Hunter had aptly called "tank fodder."
However, as he came to a point directly south of the highest point of the ridge Bob turned straight uphill, and consequently he did not emerge from the undergrowth until almost at the top. Here he dropped face downward and wriggled his way to a point where he could look down the other side-almost the same point where he had slept for a time on the night the south wall of the tank had been poured.
Activity was much as usual, with men working and children getting underfoot. Bob looked carefully for his friends, and finally decided they must either have gone to work on the boat or to stock the pool. They did not appear to be on the scene below. His father was there, however, and on him the boy kept a careful eye while he waited for the opportunity that was sure to come. He was sure, from the amount of wall still unfinished the day before, that the glazing crew must still be at work; and sooner or later they were going to need a refill. It was not absolutely certain that Mr. Kinnaird would drive down for it, but the chances were pretty good.
The uncertainty about the matter affected Bob noticeably; the Hunter, who was in a uniquely good position to observe, realized that his host was more excited than he had been since they had met. The expression on his face was utterly serious; his eyes steadily roved over the scene as the few missing or weak details of his plan were filled in or repaired. He had not said a word to the Hunter since leaving school, and that individual was curious. He reminded himself that Bob was far from stupid, and his earthly experience might very possibly make him more fit for the present activity than the Hunter. The detective had been just a little smug about his ability to think out the probable course of the fugitive when Bob had been unable to do so; now he realized that the boy was off on a line of thought at least as far ahead of him. He hoped it was equally well founded.
Suddenly Bob started to move, though the Hunter could see no change in the scene below. Without obviously trying to hide, he went downhill inconspicuously. On the ground near the mixers were scattered a number of shirts which had been left there by the workmen; and Bob, indifferent to watchers, proceeded to go through the pockets of these. Eventually he came across a folder of matches, which appeared to be what he wanted. He cast his eyes around, met the gaze of the owner of the shirt, held up the folder, and raised his eyebrows interrogatively. The man nodded and turned back to his work.
The boy pocketed the matches and strolled a little way back up the hill, where he could see the greater part of the tank floor once more. There he seated himself, and once more concentrated his attention on the actions of his father.
At last the event he had been waiting for occurred. Mr. Kinnaird appeared with a metal drum on his shoulder, and as Bob stood up to see more clearly, he disappeared below the far edge of the flooring, at the point where the jeep was usually parked.
Bob began strolling toward the neighboring tank as casually as he could, keeping a careful eye downhill. He had been in motion only a few seconds when the little car appeared with his father at the wheel and the drum visible beside him. There was no question of his destination; and, as Bob remembered, he was sure to be gone at least half an hour. He disappeared almost at once below the neighboring tank, and, owing to Bob's nearness to this structure, did not reappear at all.
Bob himself used the same tank for concealment. He kept with difficulty, to his casual pace until he had put the tank between himself and the scene of activity; then he turned slightly downhill and began running at the top of his speed.
A few moments brought him to the end of the paved road. Here the line of corrugated-iron storage sheds began; and, to the Hunter's bewilderment, Bob began inspecting them closely. The first few were normally used for construction machinery, such as mixers and graders; some of these were empty, their normal contents being in use. Several more, closer to the residential district, contained cans of gasoline and fuel and lubricating oils. The boy examined them all, stood looking around for a moment as though to get something straight in his mind, and then once more plunged into furious activity.
Choosing one of the empty sheds-he did not actually go in, but looked over about half the floor area from a point outside the door-he began carrying vast armfuls of five-gallon cans and stacking them beside the entrance. Even the Hunter wondered at the number he was able to carry, until the sound as he put them down disclosed the fact that they were empty. When the stack was built to his satisfaction, in a broad pyramid taller than the boy himself, he went to another shed and began reading very carefully the stenciled abbreviations on another set of cans. These, it turned out, were far from empty. They contained a fluid that would have passed anywhere for kerosene, although it had never been in an oil well. Two of these Bob placed at strategic points in his pyramid; another he opened, and began pouring the contents onto the stack of cans and over the adjacent ground. The Hunter suddenly connected this maneuver with the matches.
"Are you making a fire or not?" he asked. "Why the empties?"
"There'll be a fire, all right," was the reply. "I just don't want to flatten this part of the island."
"But what's the point? A fire can't hurt our friend without doing considerably worse to your father."
"I know it. But if he just thinks Dad is in a position where he can't escape the fire, I expect he might be tempted to leave. And I'm going to be standing by with another oil can and more matches."
"Fine." The sarcasm could not be described. "Just how do you expect to get your father into such a situation?"
"You'll see." Bob's voice went grim again as he spoke, and the Hunter began seriously to wonder just what was in his youthful ally's mind. As an afterthought, Bob dumped one more can of oil on the pyre, this time using a heavier fluid normally employed as a lubricant. Then he obtained a can of the kerosene, loosened its screw cap, and stationed himself across the road from his incipient bonfire at a point where he could see the dock between the sheds. He kept his eyes glued on this point, except for an occasional uneasy glance up toward the new tank. If anyone came down and found his handiwork just now, it would be embarrassing.