Jonner could not check with Sir Stanrich by radio—Mars City was too close, and they would be overheard. He had no time to spend investigating his personnel—Sir Stanrich had impressed on him that their mission must be carried out on schedule. He decided he would not tell them just yet that one of them could not be trusted. He might be able to trip the spy. But he said:
"One or more of us may be killed or captured, so I'm going to brief everyone. No matter how many of us are lost, those who are left must carry out the mission. What were you told about this?"
"I was told to meet you here and follow your instructions. I was told it's a dangerous and important assignment. That's all," said Tyruss. The others murmured agreement.
"The instructions I give you won't be mine, but those of Sir Stanrich O'Kellin, supreme commander of the Rebel forces," said Jonner. He squatted on the sand and the others crowded around in the blue twilight as he sketched diagrams with his gloved hand while he talked:
"As some of you may have learned, the Charax Rebellion is in danger of collapsing, because our supplies have been running out since Marscorp intercepted and destroyed our last space fleet from Earth. Plan Red, which was our master plan for defeating Marscorp in the field by capturing the dome-cities one by one, has failed. Regina and Charax are being evacuated because we couldn't hold them much longer anyway, and all our people are being transported around the Marscorp territory to the secret underground spaceport we established in the Isidis Desert two years ago.
"This is a temporary measure, to prepare for Plan Blue, our last-gasp emergency plan. Marscorp will no doubt find the location of the underground base by observation of the refugees, but we hope to have Plan Blue in operation before they can shift their forces from Hadriacum to the desert and break through our defenses."
"I've heard rumors of this Plan Blue," said Farlan, a slight man with blond hair. "What is it?"
"I don't know," conceded Jonner candidly. "I don't think anyone does but Sir Stanrich and a few of our top strategists. But our part of it is this:
"You may not know it, but we lost our last G-boat when we pulled that unsuccessful attack on Phobos early this year. We do have an old spaceship, riding in a polar orbit, that Marscorp doesn't know about, but no way to get up to it. Our job is to capture a Marscorp G-boat, get to that spaceship, capture The Egg and tow it into an Earthward orbit."
"The Egg?" repeated Stein, a dark, chubby fellow. "You mean that ovoid space station of Marscorp's with the antennae sticking out all over it? I've seen that thing floating up there. I always wondered why we didn't blast it."
"Not important enough," said Jonner. "It's an experimental laboratory that amplifies the magnetic field of Mars, and they've been experimenting with it as an auxiliary power station. But neither side is bothered by any lack of power from the atomic energy sources on Mars."
Tyruss appeared annoyed at this.
"Tell me something, Jonner," he demanded. "If it wasn't important enough to blast when we had the ships to do it, why is it important enough for us to capture now?"
"I don't know," said Jonner. "Those are our orders. Now, we leave the groundcars here and go on foot to Marsport. Check equipment, everyone."
"Say," commented Farlan after a moment, "I don't seem to have any sunburn lotion."
"You can have mine," said Aron, laughing. "This far from the sun, I haven't been sunburned yet, and don't expect to be."
"Haven't been on Mars a year yet, have you?" suggested Tyruss.
"No," admitted Aron. "I came from Earth with the last space fleet and escaped in a lifeboat. Why?"
"There's an Earth-sun conjunction coming up. Every time the Earth swings between Mars and the sun, everybody on Mars gets a bad sunburn. When it comes, you better cover yourself with lotion, because clothes don't protect you and even if you're in a city, the domes and house roofs are transparent to pick up the sun's heat."
"We have enough among us," said Jonner. "Besides, if our mission goes off on schedule, we'll be back at base by the time the Earth-sun conjunction starts. Let's head for Marsport."