Paul Essian was sitting at this desk avoiding the equation when the call came from Psychiatry Section. His flashboard, which took put the long wall of the office, was covered with a hash of mathematical symbols, but Essian's eyes focused through the unfinished equation to his reflection trapped behind the syrupy translucence of the board.

She shifted; crossed her legs and her arms. "Com on, Paul. What differene does it make what I or any of the other unit head think? We're on the Janus thing until it succeeds or gets canned. The problem is, this isn't the usual project - not in a lot of ways. If you slow down, there's not one to pick up the slack. The people in physics have been idle for a month; their mathematician jokes are taking on a nasty edge. I can't help you and neither can the other mathematicians. We didn't win the Prestman prize or a million dollar contract."

At the edge of his vision Essian saw the woman take something out of her purse -- a pocket flashboard. She began doing calculations and he craned his neck for a look at the display. She glanced at him and he relaized he must say something.

"Simultaneous equations?"

She laughed self-consciously. "It's hardly the place, I know, but I'm pushing a deadline. If I don't get this tonight, it'll mean a postponed vacation for me.

The bartender moved up and looked meaningfully at the two of them. "What'll it be tonight?"

The woman looked at Essian's nose cone, which was turning a rich pink as the vapors built up, trapped against the bar. "It's good," he volunteered. "Mild uppers; no primary process catalysts."

"Okay."

"One mint and quelamyne," the bartender said. "On the doc."

She looked a question and Essian made a wry face, but felt pleased. "I'm Paul Essian," he said.

"Jill Selby." Her hand seemed to fit his, returning the pressure of his fingers with perfect symmetry. "A doctor of what?"

"Theoretical mathematics."

...

"...would you like to have a try at this? She held the flashboard out to him. "I've been working on it all afternoon, but I can't seem to make it float."

Essian took the flashboard and stared at it, slowly submerging in the intricacies of the problem. The crowd noises, the music of the synthesizers and even the woman beside him slipped away as he felt his way through the trouble spots, checking and discarding dozens of routes to a solution. When he found the answer, the room around him snapped back into awareness with a suddenness that jolted him. the woman took the board, but studied his face.

"You really disappeared."

Essian realized that she was right. He had not reached such a pitch of concentration in months.

"This is it," Jill said. "Marvelous. I've never seen this proof before."

"It's in the new Esteroff text, page one-hundred twelve."