Bolan indicated a doorway beyond the top of the spiral stairway. An arrow with the Russian characters for the word Shelter pointed to a warren of passageways, which he guessed must eventually connect with the mine shaft sunk from the pithead on the ridge far above them.

Inside this opening there was a glassed-in hutch with slatted steel shutters covering the windows through which they could make out the silhouettes of two men with their backs to the dock basin, looking down into the construction chamber.

One of the men raised his arm.

Abruptly a jet of brown smoke boiled up behind the scaffolding. A muffled explosion shook the fabric of the gallery and a shock wave assaulted the intruders' eardrums. Seconds later two more detonations filled the air beneath the arcs clustered below the roof with a fog of rock dust.

Bolan and the Icelander were racing around the gallery toward the control room. By the time the whistles blew for the workers to come out of the shelter, the two invaders were concealed behind a stack of forty-gallon oil drums between the stairway and the transformers.

Now, for the first time, they were able to study the opposition at close quarters.

The Russians working in the cavern fell into three categories. The majority perhaps twenty-five or thirty were evidently skilled construction men, hard-bitten, professional, experienced. They emerged from the shelter and fled at once down the stairway to restart work on the caisson, some operating compressors and pneumatic drills, others handling concrete mixers, but most of them around the rock face behind the lock gates.

Among them were half a dozen overseers. Equipped like the workers with steel mining helmets, they were distinguished by white oilskin slickers, white boots and black arm bands each with a red star.

The third party, again perhaps half a dozen men, were of an entirely different type tough, muscular, with bleak and ruthless expressions on their flat Slavic faces.

These were the guards. They wore jackboots over the same gray fatigues that Bolan knew so well, and each was armed with a Skorpion machine pistol.

They had nothing to do with the work in progress but maintained a constant patrol throughout the base.

Two went through to the smaller cave, another couple penetrated the maze of passageways between the basin and the mine shaft, one lounged on the quay, staring down at the laborers in the dry-dock. The last strode to the gallery on the far side from the control room.

"Low-grade KGB material," Bolan whispered. "Rank and file heavies, but dangerous and efficient. There'll be more of them up top."

The control room remained unoccupied. It was obviously designed to operate the whole complex when it was completed, but for the moment orders were transmitted through loudspeaker relays from the two guys in the armored hut at the entrance to the shelter.

For thirty minutes Bolan and the Icelander watched the activity on the rock face. The guard passed their hiding place three times, but he seemed more interested in the basin below than anything at gallery level.

When he reached the far side for the third time, Bolan raised his head cautiously and peered over the top of the nearest drum.

"The two dudes behind the steel shutter are looking the other way all the time," he said quietly. "Down into the chamber. The guard up here scrutinizes the cave with the slipway at the end of his promenade. Nobody uses the control room. What do those facts suggest to you?"

"We invade the control room," Bjornstrom replied, "when everybody's back is turned."

"Yeah. It'll save time when the next whistle blows plus we can probably wise ourselves up on the eventual operations technique, which should save time when we place the charges."

As soon as the guard turned his back and leaned over the rail again, Bolan and Bjornstrom crawled out from behind the drums, sped noiselessly to the control room and slipped inside.

On the floor, out of sight below the glass windows, Bolan stifled a gasp of astonishment when he saw the complexity of equipment in the small room.

Neatly labeled in Cyrillic lettering he saw multiple banks of switch gear and levers to operate the gates and dams of the lock, controls for the shaft and elevator, the generator turbines and all the pithead mechanism.

Plus radar installations, monitor screens, a data-bank terminal, the console for a massive computer and a complete radio transmitting and receiving deck. Above the benches, the wall glittered with dials.

"No problem putting this gear out of commission," Bolan said. "Three well-placed sticks would wreck all of it. But how long is it going to take them to replace it? I think they could be back where they are today by next spring, fully operative by summer. And that just isn't good enough. What we need is some structural damage, something to damage the whole damned base so completely that it can't be repaired at all."

"You mean like blowing a hole in the bottom of the fjord and letting all the water out?" Bjornstrom joked.

"Something like that. Destroying the shaft for a start. And if we could sabotage the entrance in some way."

"But we could!" Bjornstrom was excited. "Have you noticed the state of the rock when we came in?"

"Yeah, it was weathered to hell. Dangerous too, some of it rotted enough to crumble away in your hand."

"Something else besides. There is two hundred feet of cliff above the main entrance. This is one big weight to press down on an arch that does not even have a keystone."

"You mean?.." Bolan in turn looked excited.

"I mean there is already a cracking and a partial subsidence. One big slab of granite has slipped and jammed itself across a chimney in the rock face. While it is there, all remains firm. But if it was not there..." Bjornstrom paused and shook his head.

"How much would come down?"

"I am not a professional quarryman, but I think maybe one thousand, two thousand tons."

"Right into the channel leading to the cavern? You mean it could block or at least partly block the minisubs' entry?"

The Icelander nodded.

Bolan was jubilant. "And that damage they could never repair. They could never clear the passage again because it couldn't be done secretly the whole world would see what they were doing! Can we get to this slab unseen? Have we enough plastic to dislodge it?"

"We need to fracture only one corner, then it would move. After that, the weight of the rock will do the rest. But to be sure we would require maybe ten or twelve sticks."

"Okay. We'll place the others more carefully. And the access?"

"It is not difficult," Bjornstrom said. "A crevice not far above the ledge where we came in is near enough to the slab for the explosive to work. But it must be done while everyone is in the shelter because the crevice is inside the arch and the man putting it there can be visible to any person on the quay or in the gallery."

"No sweat," Bolan said. "If necessary we'll create a diversion!"