“Pericenter,” Stone said abruptly. “How about that. Mission elapsed time one seventy-one days, fourteen hours, twenty-four minutes.” He checked his displays. “It’s the eighth of September 1985, and here we are at Venus, guys. Distance to the surface three thousand, one hundred, fifty-five miles and change. We’ve come a hundred and seven million miles from Earth, and we’re within fifty miles of the nominal trajectory. Damn fine shooting.”

York looked up, through the little science viewport above her. Her eyes seemed to have grown dark-adapted, and she thought she could see something of the cloud tops, presumably illuminated by starlight. The cloud-world looked like a huge, milky, pregnant belly, protruding toward her.

There was a flash, somewhere beneath the clouds, like a lightbulb exploding under cotton wool.

She pushed up to the viewport and stared out, “Jesus Christ.”

“What?” Stone asked.

I recognize that, from Earth orbit. “I just saw lightning, under the clouds.”

Gershon looked at her. “That’s ridiculous. You get thunder and lightning on Earth from large particles, like ice crystals, being shipped around by updrafts. Venus has a layer of stew for air. There’s no evidence for updrafts or large particles. So how the hell can there be lightning?”

It happened again: a flash, roughly elliptical, that must have covered tens of square miles. For an instant she could see detailed structure in the gray clouds, layers and banks streaked out in the direction of rotation, illuminated from below.

“Don’t argue about it now,” Stone said calmly. “If it’s there, the TV cameras will pick it up. Hell, Ralph, your fat little probe might even have heard it.”

Gershon was right, of course, York thought. There was no direct evidence on Venus of any of the mechanisms which generated thunder and lightning storms on Earth. Then what? Vulcanism?

She returned to her station, troubled. A glimpse like this isn’t enough. It’s a whole planet out there. You need a year in orbit, a wider range of sensors, a hundred probes. With this swing-by, we’re going to come away with more questions than answers.

“Makes you think,” Gershon said. “We have a delta-vee of over thirteen thousand feet per second out of that. For free. That’s more than our two tanks of propellant gave us when we left Earth orbit! And now we’re traveling at more than twenty-five miles per second, our greatest velocity…”

“How about that,” Stone said. “Natalie, as of now you’re riding the fastest man-made object in history. Quite a ride, for someone who didn’t want to be a pilot anyhow.”

York wasn’t listening.

We’re only here to steal from you, she thought. Ares had no intrinsic interest in Venus itself. We only want your energy.

Light flooded the science station. She glanced up. A new crescent was forming, as Ares swept toward the dayside of the planet.