Their café group made its own homage to the importance of nitrogen by inhaling N2O from little canisters, passed from person to person around the table. It was claimed, with marginal accuracy but very high spirits, that their exhalation of this gas would help the terraforming effort. When the canister came around to Sax for the first time, he regarded it dubiously. He had noticed that one could purchase the canisters in restrooms— there was an entire pharmacology inside every men’s room now, wall units that dispensed canisters of nitrous oxide, omegendorph, pandorph, and other drug-laced gases. Apparently respiration was the current method of choice for drug ingestion. It was not something that interested him, but now he took the canister from Jessica, who was leaning against his shoulder. This was an area in which Stephen’s and Sax’s behaviors diverged, apparently. So he breathed out and then put the little facemask over his mouth and nose, feeling Stephen’s slim face under the plastic.

He breathed in a cold rush of the gas, held it briefly, exhaled, and felt all the weight go out of him— that was the subjective impression. It was fairly humorous to see how responsive mood was to chemical manipulation, despite what it implied about the precarious balance of one’s emotional equanimity, even sanity itself. Not on the face of it a pleasant realization. But at the moment, not a problem. In fact it made him grin. He looked over the rail at the rooftops of Burroughs, and noticed for the first time that the new neighborhoods to the west and north were shifting to blue tile roofs and white walls, so that they were taking on a Greek look, while the old parts of town were more Spanish. Jessica was definitely making an effort to keep their upper arms in contact. It was possible her balance was impaired by mirth.

“But it’s time to get beyond the alpine zone!” Claire was saying. “I’m sick of lichen, and I’m sick of mosses and grasses. Our equatorial fellfields are becoming meadows, we’ve even got krummholz, and they’re all getting lots of sunlight year-round, and the atmospheric pressure at the foot of the escarpment is as high as in the Himalayas.”

“Top of the Himalayas,” Sax pointed out, then checked himself mentally; that had been a Saxlike qualification, he could feel it. As Lindholm he said, “But there are high Himalayan forests.”

“Exactly. Stephen, you’ve done wonders since you arrived on that lichen, why don’t you and Berkina and Jessica and C.J. start working on subalpine plants. See if we can’t make some little forests.”