Rainbow Mars by Larry Niven

the—” Something wasn’t translated.
    â€œThe ships further back are too slow. They won’t catch us. Some of them look like the lens of an eye. I can’t tell how big they are. I count fifteen total.”
    â€œYou have good eyes.”
    â€œYou said the crabs are part of … something?”
    â€œSeveral kinds of men gathered to make Hangtree City. The”—the translator hesitated—“Allied Peoples. There is a prophecy, Svetz. The world will dry and die. We hoped to use the Hangtree to lift ourselves to space.”
    â€œWhen did the Hangtree come?”
    â€œWhen Lord Pfee was a child. Lord Pfee?”
    A Martian answered from a higher platform. “Matth, I have a vessel to fight!”
    Matth went to join him. The two spoke. Presently Lord Pfee bellowed a string of orders, then came with Matth to join Svetz. Lord Pfee asked, “Can you see great distances?”
    â€œYes. What do you want to know?”
    â€œTell me what you see?”
    â€œAhead, nothing but desert.” Svetz zoomed his view. “Some right-angle patterns just at the horizon, right by a few degrees. Might be foundations for a city. Behind us, two ships our size and one twice as long and more flat, all at about our altitude. They’re pacing each other now, and they’re all closer than they were.”
    â€œThe markings?”
    â€œWhere would I look for them? Never mind, I see what you mean. It’s a hand, fingers spread, painted across the bow. All three ships.”
    â€œFlags?”
    Miya misread his hesitation. “Brightly painted cloth on a mast or pole.”
    Svetz knew that! “I see them. They’re flapping, I can’t read them at all. Blue on the big one, the same pattern on a little one, and the other one is yellow and red.” Svetz looked up. The banner flapping above him was yellow and black. “None like yours. One of the lens shapes is catching up.”
    Lord Pfee asked, “Weapons?”
    â€œI don’t know what to look for. The ships all have little holes in front. The big ship has two, and there are tubes on deck that look like they can turn.”
    Lord Pfee nodded. He barked rapid orders to Matth. Matth left.
    Svetz asked, “Tell me how the Hangtree came.”
    Lord Pfee peered at him suspiciously. “If I take this glass thing off you, you die?”
    â€œYes.” It might take an hour, but he’d be unconscious, unable to save himself.
    â€œWhat you threw away, wasn’t it to keep a secret from us?”
    â€œI thought it might explode and kill me. Weren’t you told?”
    â€œYes. What of this?” The rocket pack. “For flight on the tree?”
    â€œYes.” Svetz wobbled across deck to where they’d mounted it. He showed Lord Pfee how to work the rockets.
    â€œAnd this?”
    â€œNeedle gun. These needle crystals dissolve in blood. It puts animals to sleep. Enemies too, but only from close.”
    â€œNot a useful thing.”
    â€œTell me how the Hangtree came.”
    â€œI do have a ship to fight, Svetz. Still … come.” Lord Pfee led him up a ladder to a railed balcony. “I can command from here. You can use your far-vision to keep me informed. What is your interest in the Hangtree?”
    â€œWe hope to lift vessels into the sky, to the other planets.”
    â€œYes, the Allied Peoples thought so too.…”

20
    Lord Feshk ruled a city of many thousands where two canals crossed. “I was his fourth son out of fourteen,” Lord Pfee said. “Few of us are left.”
    A city of a hundred thousand or more, Svetz decided as he listened, and hundreds of klicks of canals bordered by farming land. Lord Pfee wasn’t counting slaves, children, women, elderly, or maimed: only men who could fight.
    When Lord Pfee was three, peculiar black-headed plants were found growing around the edge of a canal.
    Ten years later they were a mighty