Byr was there when she opened her eyes, standing knee-deep in the small waves just in front of her, wet-suited, golden hair damply straggled in long ringlets, face dark against the display of ruddy sunset behind, found just in the act of taking off the suit's face-mask.

"Evening," she said, smiling.

Byr nodded and splashed up out of the water, sitting down beside her and putting an arm round her. "You okay?"

She held the fingers of the hand over her shoulder. "Both fine," she said. "And the gang?"

Byr laughed, peeling off the suit's feet to reveal wrinkled pink-brown toes. "Sk'ilip'k" has decided he likes the idea of walking on land; says he's ashamed his ancestors went out of the ocean and then went back in again as if the air was too cold. He wants us to make him a walking machine. The others think he's crazy, though there is some support for the idea of them all somehow going flying together. I left them a couple more screens and increased some of their access to the flight archives. They gave me this; for you."

Byr handed her something from the suit's side pouch.

"Oh; thank you." She put the small figurine in one palm and turned it over carefully with her fingers, inspecting it by the fading red light of the day's end. It was beautiful, worked out of some soft stone to perfectly resemble their idea of what they thought a human ought to look like; naturally flippered feet, legs joined to the knees, body fatter, shoulders slender, neck thicker, head narrower, hairless. It did look like her; the face, for all that it was distorted, bore a distinct resemblance. Probably G'Istig'tk't's work; there was a delicacy of line and a certain humour about the figurine's facial expression that spoke to her of the old female's personality. She held the little figure up in front of Byr. "Think it looks like me?"

"Well, you're certainly getting that fat."

"Oh!" she said, slapping Byr lightly on the shoulder. She glanced down at her lap, reaching to pat her belly. "I think you're starting to show yourself, at last," she said.

Byr smiled, her face still freckled with droplets of water, catching the dying light. She looked down, holding Dajeil's hand, patting her belly. "Na," she said, rising to her feet. She held out a hand to Dajeil and glanced round to the tower. "You coming in or are you going to sit around communing with the ocean swell all evening? We've got guests, remember?"

She took a breath to say something, then held up her hand. Byr helped pull her up; she felt suddenly heavy, clumsy and… unwieldy. Her back hurt dully. "Yes, let's go in, eh?"

They turned towards the lonely tower.

9. Unacceptable Behaviour

I

The Excession's links with the two regions of the energy grid just fell away, twin collapsing pinnacles of fluted skein fabric sinking back into the grid like idealised renderings of some spent explosion at sea. Both layers of the grid oscillated for a few moments, again like some abstractly perfect liquid, then lay still. The waves produced on the grid surfaces damped quickly to nothing, absorbed. The Excession floated free on the skein of real space, otherwise as enigmatic as ever.

There was, for a while, silence between the three watching ships.

Eventually, the Sober Counsel asked, ~… Is that it?

— So it would appear, the Fate Amenable To Change replied. It felt terrified, elated, disappointed, all at once. Terrified to be in the presence of something that could do what it had just observed, elated to have witnessed it and taken the measurements it had — there were data here, in the velocity of the skein-grid collapse, in the apparent viscosity of the grid's reaction to the links" decoupling — that would fuel genuinely, utterly original science — and disappointed because it had a sneaking feeling that that was it. The Excession was going to sit here like this for a while, still doing nothing. Seemingly endless boredom, instants of blinding terror… endless boredom again. With the Excession around you didn't need a war.

The Fate Amenable To Change started relaying all the data it had collected on the grid-skein links" collapse to a variety of other ships, without even collating it properly first. Get it out of this one location first, just in case. Another part of its Mind was thinking about it, though.

— That thing reacted, it told the other two craft.

— To the Affront signal? the Appeal To Reason sent. ~ I was wondering about that.

— Could this be the state in which the Peace Makes Plenty discovered the entity? the Sober Counsel asked.

— It could indeed, couldn't it? the Fate Amenable To Change agreed.

— The time has come, the Appeal To Reason sent. ~ I'm sending in a drone.

— No! You wait until the Excession assumes the configuration it probably possessed when it overpowered your comrade and then you decide to approach it just as it must have? Are you quite mad?

— We cannot just sit here any longer! the Appeal To Reason told the Culture craft. ~ The war is days away from us. We have tried every form of communication known to life and had nothing in return! We must do more! Launching drone in two seconds. Do not attempt to interfere with it!

II

"Well, we were going to have them at the same time; it seemed… I don't know; more romantic, I suppose, more symmetrical." Dajeil laughed lightly, and stroked Byr's arm. They were in the big circular room at the top of the tower; Kran, Aist and Tulyi, and her and Byr. She stood by the log fire, with Byr. She looked to see if Byr wanted to take up the story, but she just smiled and drank from her wine goblet. "But then when we thought about it," Dajeil continued, "it did kind of seem a bit crazy. Two brand new babies, and just the two of us here to look after them, and first-time mothers."

"Only-time mothers," Byr muttered, making a face into her goblet. The others laughed.

Dajeil stroked Byr's arm again. "Well, however it turns out, we'll see. But you see this way we can have… whatever time in between Ren being born and our other child." She looked at Byr, smiling warmly. "We haven't decided on the other name yet. Anyway," she went on, "doing it this way will give me time to recover and get the two of us used to coping with a baby, before Byr has his… well, hers," she said laughing, and put her arm round her partner's shoulder.

"Yes," Byr said, glancing at her. "We can practise on yours and then get it right with mine."

"Oh, you!" Dajeil said, squeezing Byr's arm. The other woman smiled briefly.

The term used for what Dajeil and Byr were doing was Mutualling. It was one of the things you could do when you were able — as virtually every human in the Culture had been able to do for many millennia — to change sex. It took anything up to a year to alter yourself from a female to a male, or vice-versa. The process was painless and set in action simply by thinking about it; you went into the sort of trance-like state Dajeil had accessed earlier that evening when she had looked within herself to check on the state of her fetus. If you looked in the right place in your mind, there was an image of yourself as you were now. A little thought would make the image change from your present gender to the opposite sex. You came out of the trance, and that was it. Your body would already be starting to change, glands sending out the relevant viral and hormonal signals which would start the gradual process of conversion.

Within a year a woman who had been capable of carrying a child — who, indeed, might have been a mother — would be a man fully capable of fathering a child. Most people in the Culture changed sex at some point in their lives, though not all had children while they were female. Generally people eventually changed back to their congenital sex, but not always, and some people cycled back and forth between male and female all their lives, while some settled for an androgynous in-between state, finding there a comfortable equanimity.