They'd looked forward to many more.

Now, though, all she could think of was the fact that such crystal fields occurred in regions associated with sulfur geysers, lateral plumes, and volcanic hot spots.

Something funny was happening to the far edge of the field, though. She cranked up her helmet to extreme magnification and watched as the trail slowly erased itself. New flowers were rising up in place of those she had smashed, small but perfect and whole. And growing. She could not imagine by what process this could be happening. Electrodeposition? Molecular sulfur being drawn up from the soil in some kind of pseudocapillary action? Were the flowers somehow plucking sulfur ions from Io's almost nonexistent atmosphere?

Yesterday, the questions would have excited her. Now, her capacity for wonder was nonexistent. Moreover, her instruments were back in the moonrover. Save for the suit's limited electronics, she had nothing to take measurements with. She had only herself, the sledge, the spare airpacks, and the corpse.

"Damn, damn, damn," she muttered. On the one hand, this was a dangerous place to stay in. On the other, she'd been awake almost twenty hours now and she was dead on her feet. Exhausted. So very, very tired.

"O sleep! It is a gentle thing. Beloved from pole to pole. Coleridge."

Which, God knows, was tempting. But the numbers were clear: no sleep. With several deft chin-taps, Martha overrode her suit's safeties and accessed its medical kit. At her command, it sent a hit of methamphetamine rushing down the drug/vitamin catheter.

There was a sudden explosion of clarity in her skull and her heart began pounding like a jackhammer. Yeah. That did it. She was full of energy now. Deep breath.