They heard through their helmet phones that the mysterious dot was drawing closer. Haines set up one of the launching racks, which was equipped with a telescopic sighter, and peered through the eyepiece. Apparently he caught it, for he grunted, then motioned to Burl to take a look.
It was no natural object. It was the shape of a dumbbell—two spheres joined together by a short middle bar. One sphere was a deep, golden color, the other a bluish-silver, the connecting rod a coppery metal.
"The pattern of spheres certainly suggests the Sun-tappers to me," said Burl. Haines murmured his agreement.
Lockhart's voice came on the phones. "We've decided it's one of the Sun-tapper ships. We're not going to wait to make sure. Before we left Earth, I can now inform you, I received a directive from the President to regard the builders of these Sun-tap stations as active enemies. My orders are that we are not to attempt to undertake peaceful contact, but are to treat them on sight as armed foes in the field. To do otherwise is to risk Earth's last active defense—this ship.
"I think I don't have to argue this further, considering our recent experiences." His voice hesitated, then rang out firmly, "Haines, you can commence firing at will!"
Haines clicked his tongue and reached for one of the shells. "Okay, Burl, aim at her direct. This one's got a proximity nose that'll beam at her and drive itself where ever she ducks."
He slid the rocket shell into the launcher, Burl sighted, and then Haines pressed the trigger. There was a whoosh of fire and a flare from the launcher's nose. A minute spark winged into the darkness toward the spot, still many miles away, where the strange ship hung.
They watched with bated breath. Suddenly there was a flash of light from the other ship—a vivid lightning bolt which leaped out and flared up briefly in space. Then darkness again.
"They fired a burst of energy at us. It hit the rocket shell instead," said Haines. "Well, now we know. They use bolts of pure energy—something like the one they fired at Boulton."
He fitted another shell into the launcher, and fired again. Again a spark winged its way, and the bolt of energy burst out to detonate the shell. Burl whistled. "How did they spot it so fast?" he asked.