death.

Carefully Don lifted the limp body in his arms and turned to the door. As he did so, a muffled explosion shook the steel walls about him.

Bursting out onto the lower landing, Don Winslow collided with Lieutenant Pennington.

“Quick, Red!” he barked. “Take Jerry on your back, and get up that ladder. I’ll lash his wrists together, so you’ll have both hands free to climb with. Where are Yanos and the others?”

“They’ve just gone up!” Red answered, stooping to take Jerry’s weight. “And say! That did sound like a bomb overhead, just now! We’d better get out of here in a hurry!”

“Right!” grunted Don, pushing the other toward the ladder. “You take Jerry up and get him down to the boat. I’ve got a little job to do before I follow you; so don’t wait.”

“But, Don!” protested the red-haired officer. “I can’t leave you here....”

“On your way, Lieutenant!” snapped the young commander. “Obey orders and get that seaman down to the boat. Lively, now!”

Talking to himself in a bitter undertone, Red Pennington toiled up the ladder with his heavy burden. He’d obey those orders, all right, but Don hadn’t forbidden him to return after seeing Jerry safely in the boat. If his commanding officer was going to stick around where the bombs were dropping, a certain husky lieutenant meant to share the danger with him!

Meantime, Don Winslow had returned to the chartroom, and was hastily disconnecting the main electric cables leading to the Scorpion’s weather mapping machine.

The invention was priceless, if it could be salvaged. Heavy as it was, Don thought he might be able to carry it up the ladder.

As he worked, with flashlight and screwdriver, wrench and pliers, two more bomb explosions shook the underground base.

Little by little, a stifling, smoky odor filled the air of the chartroom. Tears filled Don’s smarting eyes, inflamed by the acrid fumes. His breath came raspingly between dry coughs.

Reluctantly he dropped his tools and fumbled for the doorknob.

“Those were gas bombs, not TNT!” he mumbled thickly, as he stumbled from the room. “Smoke’s coming down the hatch. Got to get up where there’s some—uh—air to breathe!”

As he groped toward the ladder a bulky form emerged from the smoke above him.

“Don! Don, old man!” came Red Pennington’s choking cry.

“Right here, Red!” coughed Don Winslow, clinging to the ladder’s lower rungs. “I’m—uh—all right. Coming up now. But you shouldn’t have come back!”

“Thank heaven, you’re okay!” the redhead replied. “Want me to give you a hand?”

“No! I’ll make it. Hustle, now, or the smoke is going to—uh—get us both! Where’re Mercedes and Jerry?”

Pennington’s answer was a coughing fit, which shook the steel ladder. Just below him, Don Winslow gripped the narrow rungs and gasped for breath. After a moment the two men resumed their painful climb, fighting against a growing dizziness.

“Mercedes—Jerry—on the beach!” came Red’s muffled words. “Smoke too thick to see—see the boat. Got to save breath now, and—uh—climb!”