"You must. Wait," Io said. "Ten minutes and. You can. Walk across. It. With ease."

"Son of a bitch!" Martha murmured. "I'm sane."

In wondering silence, she crossed the bridge that Io had enchanted across the dark lake. Once or twice the surface felt a little mushy underfoot, but it always held.

It was an exalting experience. Like passing over from Death into Life.

At the far side of the Styx, the pyroclastic plains rose gently toward a distant horizon. She stared up yet another long, crystal-flower-covered slope. Two in one day. What were the odds against that?

She struggled upward, flowers exploding as they were touched by her boots. At the top of the rise, the flowers gave way to sulfur hardpan again. Looking back, she could see the path she had crunched through the flowers begin to erase itself.

For a long moment she stood still, venting heat. Crystals shattered soundlessly about her in a slowly expanding circle.

She was itching something awful now. Time to freshen up. Six quick taps brought up a message on her visor: Warning: Continued use of this drug at current levels can result in paranoia, psychosis, hallucinations, misperceptions, and hypomania, as well as impaired judgment.

Fuck that noise. Martha dealt herself another hit.

It took a few seconds. Then–whoops. She was feeling light and full of energy again. Best check the airpack reading. Man, that didn't look good. She had to giggle.

Which was downright scary.

Nothing could have sobered her up faster than that high little druggie laugh. It terrified her. Her life depended on her ability to maintain. She had to keep taking meth to keep going, but she also had to keep going under the drug. She couldn't let it start calling the shots. Focus. Time to switch over to the last airpack.

Burton's airpack. "I've got eight hours of oxygen left. I've got twelve miles yet to go. It can be done," she said grimly. "I'm going to do it now."