"Retreat!" Doc commanded his friends. "We're between the gang and their boats. We'll try to keep them from reaching the craft."

They were extremely thankful for the rugged surface of the iceberg, now that the situation had changed.

Doc found a small crevice in the ice. Into this he lowered his bundle. With a single rap of his tempered fist, he shattered enough brittle ice to conceal the bundle.

Captain McCluskey's booming voice reached them.

"The deck swipes!" thundered the walrus. "Put the lot of 'em in Davy Jones's locker!"

"They don't seem to be trying to beat us back to the boats!" Doc said in a tight voice of wonder.

A storm of lead scored the ice all about. The Helldiver gang had caught sight of them.

Ham whirled. He secured a glimpse of a fur-swathed head.

His rifle jarred. A man slouched out from behind an ice spike and lay down as though tired. Steam curled up from the scarlet pool that gathered around his feebly squirming body.

"I haven't lost my shooting eye!" Ham said with grim mirth. "Did you see who I winged?"

"Dynamite Smith, the oiler," Doc retorted. "Let's veer over to the right here. It looks like better footing."

There ensued a frightful couple of minutes before they reached the spot Doc had indicated. The more frantic the effort they put forth, the more they slithered around on the terrifically rough and slippery ice.

"Seas have been breaking over this berg recently," Doc explained. "That's why it's so infernally slick."

Bullets gouged ice around them like hard-driven, invisible picks. Ricocheting, the lead squalled like unseen wild cats.

Doc, Long Tom, Ham, and Johnny finally reached the smooth footing which Doc had indicated. This was a great crack which had opened in the berg, filled with water, then frozen. They glided down it.

"We're gonna beat 'em to the boats, anyhow!" said the bony Johnny. He had taken off his glasses with the magnifying lens on the left side. His breath steam had been fogging the spectacles. Johnny really did not have much need of glasses on his good right eye, anyway.

"It's funny they're not putting up more of a race to keep us from reaching the boats!" Long Tom snapped. "I don't understand it!"

But they did understand it a moment later.

They came in sight of the boats — more properly, the spot where the boats should have been, for the craft were gone.

And the submarine was not where they had left it!

"THEY'RE CLEVER rats!" Doc Savage said grimly. "The men who remained aboard the Helldiver put another folding boat in the water the instant we were out of sight. They secured the craft we left on the ice. And look — there's why McCluskey's gang were not so ambitious in pursuing us." A bronze arm pointed.

The three stared. Their hearts sank.

The Helldiver had cruised down the edge of the iceberg. Standing by, the submarine was picking up members of the villainous crew as they slid off the sheer edge of the vast pan of ice.

Doc's pals opened fire with their rifles. The range was considerable. A high tribute to their shooting was the fact that they put two of the Helldiver crew out of commission.

The rest of the sailors reached the submarine safely. The craft sped down an open lead in the pack ice, headed northward. It was making for the spot where, according to the map, the liner Oceanic lay. The dense mist swallowed the sub completely.

The last thing they saw was the gigantic figure of Captain McCluskey standing on deck, shaking both his fists in their direction.

"Brothers!" Doc said mildly, "we have been guilty of an unforgivable mistake."

"What's that," Ham wanted to know.

"We underestimated the intelligence of friend McCluskey," Doc replied. "Some days ago, McCluskey commented on the furtive actions of his own crew, giving the impression, he, himself, feared trouble from them. The clever fellow must have been aware I had noticed the attitude of the crew, and he expressed himself thus to allay my suspicions of him."

"They've got the treasure map, of course," Ham clipped. "They've set out to grab the treasure."

"And they've left us in a pretty serious position," Johnny muttered. "Marooned on this arctic ice pack is tantamount to a sentence of death."

Johnny's words carried awful portent Johnny knew the polar regions. It was a part of his profession. And if he said their situation was bad — it was really bad!

"We might as well realize we're up against it," Doc told them, "and stop talking about it."

"The racket scared the walrus off the floe," Long Tom grumbled, his unhealthy-looking features drawing deeper into the hood of his fur parka, like the head of a turtle into its shell. "We're without grub!"

Ham whipped his bearskin trousers vigorously with his sword cane. "I've heard of Eskimos living quite a while by eating their clothes," he said.

"We won't need to start on our wardrobe for a while:' Doc smiled. "We have concentrated rations for about a month."

"Where?" the others yelled in chorus.

"In the bundle I brought along," Doc replied.

THE PARTY retraced their steps to secure the all-important bundle Doc had cached in the ice crevice.

There was no excitement now. They had leisure to realize the full peril of their predicament.

The deathlike quiet of the polar wastes had enveloped them. The stillness was as of a tomb.

From time to time, the awful silence was shattered by a crashing roll of sound like thunder. These noises would start with a report sharp and loud as a cannon crack, and there would follow an increasing volley until the very ice under their feet seemed to quake.

This was the awesome voice of the ice waste — it was simply cracks opening in the floes.

"Nice music!" Ham shuddered.

Thoughts came to them of Renny and Monk, of the death both giants seemed certain to have suffered. This depressed them.

There was a quality of horror in the grisly spells of silence. It was as though they existed in some weird, frozen habitat of lost souls. They found themselves listening with an eagerness near pathetic for the sporadic cannonade of the ice — then shivering when the sound did come.

Only big bronze Doc Savage showed no emotion. He swung along easily, keeping his feet on the slick iceberg under foot as surely as though his mukluks were arms with steel spikes. Often, he waited for his three friends to overhaul him.

The mighty bronze man seemed to sense that his very presence offered a bolster to the courage of Long Tom, Ham, and Johnny. So he remained near them, although the best pace they could manage was but the speed of a snail compared to the swiftness with which Doc could have reached the cache.

They secured the bundle from the crevice in the ice.

Doc let his men squat around it. They went to work on the wrappings with cold-stiffened fingers. The more they kept busy, the less they would brood over their fearsome predicament.

Suddenly, Ham gave a start — stopped fiddling with the knots.

To his ears had come the low, exotic trilling sound which was part of Doc. So low, so nearly unreal was the mellow note that it was almost lost in the fearful silences about them. It might have been the voice of some fantastic sprite of this domain of cold.

Ham grasped his sword cane. Johnny and Long Tom became rigid as the ice hummocks about them.

Doc's trilling slipped away into nothingness in a manner as intangible as its coming.