Covered by their own echoes, he stole up on the men ahead. His groping hand brushed gently against the clothing of the last man in the group. Gauging his distance swiftly, he went into action.
One hand fastened over the fellow's mouth. The other, holding a good-sized rock, struck down behind the ear. Gray eased the body down with scarcely a sound.
Their uniforms, he had noticed, were not too different from his prison garb. In a second he had stripped goggles, cap, and gun-belt from the body, and was striding after the others.
They moved like five eerie shadows now, in the queer light of the leader's lamp. Small fluorescent markings guided them. The last man grunted over his shoulder,
"What happened to you?"
"Stumbled," whispered Gray tersely, keeping his head down. A whisper is a good disguise for the voice. The other nodded.
"Don't straggle. No fun, getting lost in here."
The leader broke in. "We'll circle again. Be careful of that Project bunch—they'll be using ordinary light. And be quiet!"
They went, through connecting passages. The noise of Dio's party grew ominously loud. Abruptly, the leader swore.
"Caron or no Caron, he's gone. And we'd better go, too."