The frogmen

  "It's the nineteenth, Commander," Amos said. "Just take it easy."

  Tanaka's eyes were wide open, staring at the rock ceiling. "I can't remember," he said. "I just can't remember. Not for the nineteenth."

  "We got lots of time," John said. "Just a heap of

  it.

  "You take a little snooze," Max said. He pushed part of the wet suit up under Tanaka's head. "Here. Now just shut your eyes and take a little snooze."

  Amos went over to the spare tanks, fitted two fresh ones into his harness, and slung the pack into place. As he buckled up, he said, "I'm going out to take a look."

  "At what?" John asked.

  "Around." Amos selected some tools out of the box and put them into the canvas tool bag hanging from his belt. "Check me for magnetic, John."

  "Amos, ol' buddy," John said, "you're not getting the picture. Without the boat, we can't go anywhere. Without the radio, we can't talk to anybody."

  "We've still got mines," Amos said, "and we've still got the coding board. Just check me, John."

  John glanced over at Tanaka, who was either asleep or unconscious. "Mines, we got. But if he can't remember the keys, that coding board is just a piece of wood."

  "Come on," Amos said.

  "Amos," John said quietly, "let's just sit down and eat something and talk this thing over. Okay?"

  "No," Amos said. "Anyway, we might be in here a long time, and we'd better start planning not to eat anything until we have to. And then not much. So check me out, John."

  John came over and reluctantly began checking. "What for, Amos?"

  "Because I don't want to sit around in here," Amos said. "It makes me nervous."

  Max was sitting beside Tanaka, his feet in the water. "You know, I used to be pretty good at doping out where the ball was going." His voice sounded soft and remote in the silence of the cave.

  "Got to get rid of that knife," John said, unhooking the scabbard from Amos' belt. "Must be solid iron. Here, take mine."

  "So I'd be there," Max said. "Waiting for him. It was a good feeling to see that surprised look on his face when he saw me where I wasn't supposed to be. And he always looked a little sad too."

  "Okay for magnetism," John said.

  "But every now and then I'd dope it out all wrong, and the man I was waiting for wouldn't have the ball, and he'd look at me and grin and I'd look around, and the man with the ball would be long gone. It used to make me feel useless. Just downright useless."

  Amos looked over at him, pulled the mask down, and fell forward into the water.

  It was the first time Amos had been in the channel under a cloudless sky with the afternoon sun throwing dark shadows from the brilliant growths of coral. All around him now were bright fishes and vividly colored corals, and the water was so clear that it was hard to remember it was there, completely surrounding him.

  The rows of gray mines stretched out across the channel, hundreds of the alien things, their silence, their lack of motion and color making them ugly.

  The shadows of the mines were long across the bottom as he swam over to the one closest to the cave mouth and hovered above it.

  The part he could see was a flat-topped cylinder about five feet tall and three feet in diameter. He could not tell how much more of the thing was imbedded in the sandy bottom.

  The four contact horns set into the flat top about three inches in from the outer rim looked to him like standard Hertz horns; just hollow lead tubes, closed at the top and sticking up from the case about four inches.

  The square metal box, which he assumed was the firing mechanism, was set between the horns in the center of the top.

  Amos had never seen a mine like this. He lay in the water a long time, studying it, before he drifted down a little and, at last, reached out to it.

  He put his bare hand gently on the curved metal case, letting his fingertips touch it lightly at first, then pressing a little harder until his hand was flat against the mine.

  It was the same temperature as the water, and he could feel no movement at all.

  With both hands on the mine, his finned feet holding him steady, he drew in closer and then, holding his breath to stop the rattling of his exhaust air, he put his ear against the mine.

  He heard nothing moving inside it, no clock ticking, no movement of gears or wheels.

  Turning loose, he moved slowly down the mine, stopping to examine a heavy metal belt, equipped with three lifting rings, that was bolted to the case about a foot down from the top. He could not tell

  whether the belt concealed a matching of the two parts of the mine or whether it was simply bolted to a solid section of the cylinder wall.

  Amos swam on down to the bottom and started digging a trench around the mine, staying far enough away so that his digging would not cause the mine to topple over.

  He dug down at least two feet into the soft sand but found nothing. No wires that could lead to some control station on shore and no explanation of why the mines remained in place, upright, although they would be swept by fairly strong currents during heavy storms.

  Going back to the top of the mine, he put his hands on the rim to hold himself steady and moved close to it.

  There was nothing remarkable about the Hertz horns, but from this angle he was surprised and puzzled by the construction of the firing-mechanism enclosure.

  Instead of a solid metal box, this thing was made up of four half-inch metal posts welded to the top case of the mine and supporting what appeared to be a fairly heavy-gauge square metal plate. The plate and posts made a small, rugged, square table standing on the mine, the level of it just below the tips of the horns.

  Amos was also puzzled by the fact that the four areas bounded by the posts, the plate, and the mine were not solid metal but appeared to be heavy bronze screen wire.

  Moving around to face the sun, he could see that he was right; they were screens, held in place by metal strips screwed to the posts. There was something inside the screens that looked like a solid metal cylinder.

  Taking a new grip, and checking to see that no part of his body or equipment could touch one of the horns as he was moved by sea currents, he drew himself in closer until he could rest his chin on the rim of the mine, each ear equidistant from a horn.

  Now he could see that the screen in front of him was held in place only by the strips on two sides and a small channel at the bottom. There was nothing holding the screen at the top, where it came up to the edge of the metal plate.

  With the sun at the angle, all he could see beyond the screen was the solid, curved metal of what looked like a can, about a foot in diameter, attached to the top of the mine and extending up to about an inch from the bottom of the plate.

  He could not look down at the top of the tin can; all he could see was a flat, dark surface, unmarked by any bolts or screw heads.

  Moving very carefully he went all the way around the mine, studying each screen and the can inside, but found nothing more.

  For a moment he lay there, just staring at one of the screens.

  In Death Row, the Hangman enjoyed issuing a warning that at the time had seemed stupid to

  Amos. "Never make a move with a mine," he would say, "unless it's the right one."

  Now Amos understood it. It wasn't stupid at all.

  It looked to him as though it would not be too difficult to grasp one of the screens by the top and pull it straight up and out of the strips holding it in place. The strips didn't look as though they had been bent in to hold the screens firmly; they were only retainers.

  Or had the screens been intentionally designed to slide easily?

  If the screens were there only to protect something inside that tin can, then lifting one out would be the right move.

  If the screens were an integral part of the firing mechanism and moving one would start the firing sequence, it would be the wrong move.

  "If you don't know what you're doing to a mine, don't do anything," was another of Hingman's sayi
ngs. "If you don't know why you're doing something, don't do it."

  The way the screens were held in place was so simple that Amos wondered if the enemy would set up such an obvious trick. If contact of the screens with the posts kept a circuit open, and to remove one would close the circuit, then a man could just move one up enough to see inside without breaking the contact.

  If there was a wire attached to the bottom of each screen which, when a screen was moved up, would pull some mechanism or make some contact, that

  wire could easily be seen by moving a screen upward only very slightly.

  But if the bottom of each screen held some tension device in place so that any upward movement at all would fire the mine, then there was no way to tell.

  On the other hand the screens might be there only to keep fish and crabs and floating debris from striking the tin can inside.

  But why screens? Why not solid metal?

  Amos moved slowly around the mine, inspecting each screen.

  He stopped at the third one. Either it had not been set in place all the way or some current or blow had loosened it, for the bottom edge was about one sixteenth of an inch above the little channel in the mine top, so that he could see the crack all the way across.

  There was no wire or anything else attached to the bottom of the screen and no evidence of any sort of pressure device.

  That left only contact.

  Amos moved away from the mine to slow his breathing and relax.

  Going back to the mine, he moved gently but firmly against it and carefully wrapped his legs around it, letting their pressure bring the buckles of his gear in contact with the mine without jarring it.

  With one hand he reached out to the rim and grasped it firmly, holding himself so that his eyes were on a level with the screens.

  When he was securely in place, almost a part of

  the mine, he let his fingertips just touch the metal top and moved his hand in toward the device in the center. He kept watching both his hand and his arm to be sure that no part of him came in contact with the lead horns.

  Before touching the device, he closed his hand so that only his forefinger was extended.

  The sound of his exhaust air was too rapid, so he waited, his finger a fraction of an inch from the screen, until his breathing slowed again.

  The screen looked so innocent. He touched the wire with extreme delicacy, letting his finger rest there for a long time.

  Then he pressed gently and felt the screen give very slightly.

  Watching his arms and the nearest horn, he walked his fingers slowly up the screen and gripped the top of it between his thumb and forefinger.

  He began to pull, his arm rigid between the horns, the curved rim of the mine pressing up against his lower lip.

  The screen moved upward slowly, and he looked beyond it, searching for any wire or lever that might be moving up with it.

  There seemed to be nothing attached to it, so he lifted it until it was clear of the can inside but still in contact with the metal strips on the posts.

  The round, metal can inside the screens was about twelve inches in diameter and was attached to the top of the mine.

  The cylindrical surface of the can was perfectly

  bare; there were no bolt or screw heads visible; there was nothing attached to it.

  With a steady movement he let his fingers touch the can and slide slowly around it, being careful to keep his wrist from pressing against the support post.

  The can was bare all the way around.

  Withdrawing his hand again, he raised his head an inch, his chin sliding up the rim of the mine, and looked in at the top of the can.

  At first sight the top seemed as bare as the sides, just a metal top; half a coffee can stuck to the top of the mine.

  Then he noticed that the top was not perfectly flat. There was a small corrugation which ran all the way around it just inside the rim. As he studied this he could see now that there seemed to be two different metals in the top. From the rim in an eighth of an inch to the corrugation was some grayish material, perhaps aluminum; the rest of the top, inside this corrugation, was black.

  He moved his fingers until his forefinger was delicately in contact with the top.

  Somehow the surface did not feel like metal.

  As his finger lay gently on the black stuff, Amos suddenly felt the movement.

  It was as though he were touching something alive; it had a slow, faint, steady pulse.

  His first instinct was to jerk his hand away, and his muscles snapped into motion.

  At the same time, other muscles reacted against them, stopping any motion of his hand.

  One thing he had learned in Death Row was never to jerk your hand away from anything; never make a fast movement around a mine.

  So he let his finger lie there on the pulsing, living top, the life of it streaming up through his nerves and terrifying him.

  Slowly he began to realize that the pulse was in rhythm with the wave action of the water, the stuff under his finger moving slightly up and down as the waves moved over the surface of the sea, rising and falling.

  The thing was some sort of diaphragm made of either very thin metal or rubber or perhaps some flexible type of plastic.

  It was very difficult for him to hold his finger there, neither pressing more firmly nor relaxing the pressure, as he realized that this diaphragm's movement was somehow a vital part of the mine's firing mechanism.

  Without any change of pressure, Amos moved his finger slowly over the black surface.

  Something hard and sharp was sticking up from the surface of the pulsing top.

  He moved his head up to a better position and, to keep any vibration out of the glass face plate, stopped breathing.

  Moving his finger up and away, he looked in at the surface of the can.

  A small-gauge wire or rod, cut at a sharp angle with pliers, stuck through the diaphragm and was

  held there by what looked like a grayish glue or lead solder.

  It reminded him of the wire from a magnet where it is attached to the cone of a loudspeaker.

  Amos slowly slid the screen back into place and moved away from the mine, lying in the water just looking at it.

  There was no explanation for the pulsing diaphragm, no reason for the wire. No mine exploder he had ever seen or read about had anything like this in the firing cycle.

  Amos realized now that he had been breathing with difficulty for some time and almost panicked before remembering that he had not yet turned on the reserve air. Reaching back for the valve, he turned and headed for the cave entrance.

  Tanaka looked dead, but Max said, "No, he's asleep."

  "How is he?" Amos asked as he started changing tanks.

  "Bad, I think. Real bad. He gets blood in his mouth."

  Amos winced and looked over at him.

  "One of the broken ribs might have gone into his lung or something," Max said. "How's the mine?"

  "Bad, too," Amos said and told them what he had found. "I just don't know what the thing on top does, what connection it has with anything."

  John moved around so that he was facing him. "Are you going back out there, Amos?"

  Amos nodded.

  John was angry. "You don't even know if the things armed! You don't know anything!" He lowered his voice and said, "Amos, drop it! Forget it. Even if you're lucky and take the stupid thing apart and lay it all over the bottom, what good can it do? We can't talk to anybody. We can't tell anybody what you find. Amos, why take a chance on getting killed out there? For nothing."

  "I ran out of air before I got a good look at it," Amos said. "That's all I want to do. Just take a look."

  "Okay, I'll go with you."

  Amos didn't want him out there at the mine. There was nothing he could do. "I'd rather you didn't, John."

  "Amos, do me a favor, will you?"

  Amos said to Max, "All he wants is a one-way ticket to Savannah, Georgia."

  "That, too,"
John said. "No, just this, Amos. You're not kidding anybody, so when you start tinkering with that mine, don't go so far into it that you can't just turn loose everything and back away from it."

  "I'm just going to look at it!" Amos said angrily. He was afraid of the mine now and he didn't want John making it worse.

  The tools were all made of bronze or non-magnetic stainless steel. At the mine, Amos carefully selected the ones he would need and put the rest of them, still in the bag, down on the bottom.

  He was laying the tools out on top of the mine, being careful not to hit the horns with them, when

  he heard the thrum of propellers above the usual small underwater sounds.

  He moved down into the shadow of the mine and looked over the top of it at the ship coming toward him.

  The thing was huge, the bottom badly in need of scraping and painting, barnacles thick on it everywhere except on the shafts and blades of the four propellers.

  Only two of them were turning, revolving very slowly, the great blades barely moving the water against the barnacle-encrusted rudder.

  The ship passed directly over him, plunging him into almost complete darkness, and then it was gone, fading away into the lagoon.

  The mine had not moved or made any sound.

  As Amos set to work he reviewed eveiy method he knew of causing a mine to contact a ship's hull and destroy it, but there was nothing on this mine except the Hertz horns. At the bottom of those thin-walled, hollow lead horns were two bare wires which, when current was generated, would fire the mine. The wires extended up a little way through the lead, just sticking up into the hollow with no current in either one of them. But above them, held by the lead, was a fragile glass vial. When the horn hit something—and it didn't have to hit it hard— the thin lead casing around the vial would collapse, shattering the glass.

  The fluid in the vial was an electrolyte, probably potassium bichromate, which, when it ran down

  around the two bare wires, created a miniature battery with enough current to start the whole process of firing the mine.