The tug rounded the curve of the treetop with a virtuoso application of lateral jets by Lydis. Ahead, the dragonfly bubble rose into view. Its pilot was applying the brakes with a skill that matched Lydis’s. It hovered a bare quarter mile above the crown of leaves, its chemical jets scorching the branches. The other bubbles were some tens of miles away, not yet a threat.
The opalescent sphere crowded the viewport. With sickening clarity, Bram saw hundreds of space-suited nymphs crawling over its surface, ready to swarm over the branches at the instant of touchdown.
The tug hit it broadside with its cushioned nets. The work vehicle was a mere speck next to the sphere, but its powerful engines had moved comets larger than this.
Bram saw a shower of nymphs wriggling against the void, shaken loose by the impact. The pilot of the bubble frantically tried to bring his own maneuvering jets into play—either to try to burn the tug or to slip out of its clutches. He and Lydis dueled, two masters of the pilot’s art. But Lydis anticipated every parry. Slowly she drove the hovering bubble off its landing pattern, moving it farther and farther along a tangent away from Yggdrasil.
The bubble’s main thruster was pointed down toward the tree, still spouting fire and helping Lydis. There was only one way the pilot could hope to break away from the mite that was pushing so hard at his ship. He turned the braking blast on full force, driving himself away from the tree so that he could start over again—and incidentally char the tug to a cinder.
Lydis was ready for him. The instant she felt herself losing contact, she spun the tug one hundred eighty degrees on its steering jets. By the time a haft mile of globe had slipped past her, she was zooming away at full acceleration. It was the dragonfly bubble that was licked by her flame.
Bram could see the cloudy orb fighting for control. They were still alive in there, but they were in trouble. The nymph pilot was trying to spin the globe around so that he could kill his outward momentum and dive toward the tree again, but his key maneuvering jets must have been damaged because he could achieve only an erratic wobble.
Again, he did the only thing he could. He cut the main jet to stop his headlong outward flight and began, slowly and painfully, to spin the sphere around by some internal means.
“Either they’ve got a whopping big flywheel in there,” Jao said, “or there’re thousands of nymphs running around an inside track.”
The globe receded into the distance. But the rest of them were drifting toward the giant tree like a clot of foam.
But by this time, Yggdrasil itself was moving beneath them. Bram saw the bright ball of the fusion sun in its cage, shining through the polarized disk that had appeared on the viewport to eclipse it. A brilliant pathway of hadronic photons reached thousands of miles into space, like a sword with the probe as its haft.
“Now to get down there before they build up to a g,” Lydis said through clenched jaws.
Her fingers flew over the console, and the tug began its downward descent.
An incoherent choking sound came from the curator. “L-look, they’re all over us!”
Bram whipped his head around. All of the viewports were filled with dragonfly faces, boxed in glass. Armored claspers hammered at the hull.
“We’re covered with them,” Lydis said. “They must have swarmed over us when we jolted them loose.”
“How many?”
“I don’t know. Tens of them, maybe.”
Jao assumed a noble pose. “We can’t take them back with us. We’ll have to—
“Too late,” Bram said. “Some of them are already breaking free. They can drift down to Yggdrasil on their own.”
“There’s only one thing to do, then,” Lydis said. “Deliver them to one spot.”
She conferred by radio with Jun Davd. The outside defenders were alerted. They were all keeping their eye on the approaching tug. A flare went up to indicate where Lydis should try to land.
It was tricky. Fortunately, they were headed toward the leading edge of the tree crown, so there was no danger of sliding down the effective side of an accelerating object and falling into the photon stream. But Lydis had to contend with a rough landing field whose surface was rising toward her at an increasing but unknown rate and whose counterfeit gravity was mounting by the second.
Jao tried to help her with the variables and derivatives until she told him to shut up and let her concentrate.
Below, where the flare had been, Bram could see a ring of bobbing lights—men and women with torches. The ring expanded, dispersed, as the defenders scrambled outward, away from the touchdown point.
From all directions, other lights converged on the target ring as other defenders abandoned their positions and came to help.
Bram waited out the descent, sweating. A nymph scrabbled at the viewport opposite him and seemed to be making progress in creating a loose place for prying away the frame.
Then the nymphs were hurling themselves away from the hull, abandoning the tug before it touched down and spreading outward to get away from the rocket blast.
“Hold on!” Lydis cried.
She cut the drive twenty feet up, motionless in respect to Yggdrasil. But Yggdrasil continued to accelerate, and when it met the undercarriage of the tug, there was a respectable jolt. The tug settled into a nest of charred leaves, broke through smaller twigs, and came to rest at a crazy angle.
Bram hoped the landing had been as hard for the nymphs that had jumped ship before the impact. He saw one snatch at a twig, miss it, and smash its glass helmet against a projecting branch. But other nymphs were managing to land right side up or to grab branchlets with their four legs and abdominal claspers and swing themselves around.
“Let’s go!” Jao roared, and he headed for the air lock with a grappling hook in his hand.
“Stay inside!” Bram said sharply.
Jao turned slowly around, an incredulous expression on his face.
“We’d only get in their way,” Bram said. “We’re inside the circle with the nymphs.”
The curator sat with his teeth chattering, hugging his portfolio to his knees. It would have been an injustice to say he looked relieved.
Bram went with Lydis and Jao to look out the main port. Methuselah leaped off his shoulder and scampered ahead of him, taking a lively interest in the proceedings. “That’s right, old fellow,” Bram said, patting his head. “We’ve got lots of friends out there.”
The circle of torches converged inward, making a pool of light as big as a teamball field. Bram saw the flickering nymph figures darting back and forth amidst the shadows of leaves.
One of them made a run at the perimeter of the circle. It was met by a hail of small thrown objects. It scuttled back and forth, trying to escape, but several missiles found their target. The glass helmet flew apart in fragments. There was a brief greenish snowstorm within the square frame, and the long tubular body curled up in the agony of death.
The circle of lights moved inward. Bram could see more lights rising above the sharp curve of the branch’s horizon and approaching in ragged lines from the longitudinal directions.
Another dragonfly made a rush and was driven back by brickbats. The circle of lights contracted again.
“Throwing things,” Bram said. “That’s what Ame says our treetop ancestors were good at. It gives us a longer reach than creatures like these. They don’t understand throwing.”
“They’re learning,” Jao said. “Any minute now it’s going to occur to them to rush in a group, and then some of them will break through.”
Bram glanced at the approaching lights. Reinforcements. He wished they would hurry up.
“We’d better get out of this system fast,” Jao went on. “Because the next time we meet these things in space, they’re going to be wearing wire mesh over their helmets.”