When Austin went to retrieve the sword, the knife slashed the air a few inches from his chest. Barker kicked the sword out of reach, then advanced on Austin. He stepped back and felt the edge of the desk behind him. He could go no farther. Barker was so close, Austin could see his face reflected in the sunglasses. Barker smiled and raised his knife to strike.

Zavala had bounded through the doorway and stopped short. He expected to find himself in another corridor. Instead, he was in a small chamber, not much bigger than a telephone booth, with ladder rungs running up one wall. A single wall lamp lit the cramped space. Under the lamp was a flashlight rack. One of the lights was missing. He grabbed one of the remaining flashlights and pointed it up. He thought he saw a flicker of movement in its beam, then nothing but darkness. He slung the rifle over his shoulder, tucked the light in his belt and began to climb. The shaft opened onto a passageway con- structed in a triangle of interlocking girders. Probably part of a keel that kept the airship rigid and allowed access to its innards.

The keel intersected another passageway. Zavala held his breath and heard a slight ting that could have been made by a boot or shoe slapping against metal. He stepped into the new passageway and found that it curved up against the inside of the zeppelin's skin. The white fabric of the inflated gas bags was pressed tightly against the framework on the other side. He guessed that he was inside a ring that worked with the keels to give the airship further support.

His theory proved out, as the passageway began to curve back on itself, so that he was climbing directly over the huge bags. Zavala was in good shape, but he was panting heavily when, at the top of the zep- pelin, he came to another triangular passageway running lengthwise from the front to the back of the airship. The choice was easier this time. He pointed his light along the transverse support. He could see movement and hear heavy footsteps echoing in the distance.

Zavala dashed along the keel, knowing he had to stop Scarface be- fore he made it to the control car and raised the alarm. He came to another juncture where the transverse corridor intersected a sup- porting ring. There was no sign or sound of Scarface to reveal where he had gone. Zavala's mind assembled a picture of the inside of the great airship.

If he were looking at a clock, the corridor he was in would be in the noon position. The transverse passageway he had seen earlier was at eight o'clock. To keep the rings rigid, there must be a third horizontal passageway at four o'clock. Maybe he could cut Scarface off at the pass.