"Oh dear," Executive Officer Joan Rubilio sighed. "I'm spending a lot of time with Mr Barry."

She and Gillian were in the 1G Bar, a structure built in the style an old English pub,  located in a pleasant grove of trees in the rim park. As in the Navigation centre, viewports dotted the bar's floor and stars wheeled below their feet. Beyond the grove, they could see across the meadows to the forest of the East Side.

It was one week after the meeting in Captain Xing's conference room. Captain Xing's action assignments were in progress. Gillian had begun her training as a Walker, and she was growing friendly with Captain Xing's officers.

"I've got two activities with Mr Barry. I'm working with him on the survey of passenger morale, and testing volunteers for more candidate Walkers." Joan made a face and sipped at her wine.

"What's your problem with him?"

"Overbearing, impatient, inclined to rush off and do things without discussion." Joan gave a rueful smile. "But apart from that, he's ok."

Gillian wanted to be sympathetic, but her new life was too absorbing. She was well into her short training course, redesigned by Mr Dryen and his committee. She spent much of her spare time relaxing with her friend, Celia Ho, in the Half-G coffee lounge on the lower East Side, Walking in the rim park and sometimes lounging in her cabin. These environments were comfortable for them. Occasionally, they visited Celia's cabin, but the attentions of Celia's attentive and solicitous parents were constraining.

The Executive Officer had invited Gillian and the rest of Captain Xing's committee for a relaxing  'how are we all progressing' drink. They were waiting for the others to appear; the Exec and Gillian were early arrivals.

Gillian had never entered a public bar before because she had been too young. This was a new experience for her. She said, "Mr Barry does seem to be a difficult person, doesn't he? Perhaps he has big numbers invested in this trip."

Joan nodded. "You could be right."

"But I wonder why he was the one who mentioned the possibility of waiting to see if Abel recovers?"

"Perhaps it was just a sham to make us think better of him?"

Gillian did not know what to think of this idea. "How's the wine?" she asked.

"Good. It's a light white, not too sweet."

"I'd like to try a sip."

"Not here, you can't. Too many people are watching."

Though Gillian, at an assumed eighteen years of age, was allowed inside the bar, ship's regulations still deemed her too young to drink. So she fiddled with a juice concoction that Joan had purchased for her. She was not even allowed to go to the counter by herself and spend a few numbers on something non-alcoholic.

Gillian knew that other people in the bar were staring at them. Her face appeared on the ship news channel almost nightly, along with advertisements for other young people to apply for Walker training positions. She kept her gaze on Joan.

As intense and anxious interest from the rest of the ship had begun to envelope her life, she was feeling pressured. Outside her cabin and the Navigation centre, she was always conscious of the stares and curiosity directed at her.

Celia had tried to reassure her that the passengers she knew were realistic, and did not expect her to perform a sudden rescue. Gillian had responded to her friend, "Are you going to apply for testing as a Walker? It would be wonderful if they accepted you!"

Celia had looked sad. "I already applied, but I failed the tests."

Gillian had nursed a dream of having Celia join her in her new life: someone familiar to share the pressure with her, and the occasional scare.

She asked Joan Rubilio, "Are you still working with Mr Dryen on the last version of the nav software?"

"We're still examining the feasibility of it. Mr Dryen is more comfortable to deal with than Mr Barry."

"Good. I thought Dryen seemed touchy when I first met him at the Navigation centre, but we're working well together now."

"I'm glad to hear it. We're identifying the system features we lose if we downgrade, identifying the problems of that, and any adjustments we'll need to make to your training." Joan paused. "I suppose he must have told you about this already?"

"No, not much. We're both pretty busy as it is."

"How are you feeling so far, Gillian? I mean, about becoming a Walker, and the training load."

"It's definitely demanding, but I think I can manage it. It's all so interesting!"

Until now, Walkers had always educated other Walkers, supplemented by informal material put together by their peers and certain mandated navigator training elements. It was like a guild system, where apprentices worked with masters of the trade.

"And about Walking itself?"

"Excited!"

"Not scared? After what's happened to the other two Walkers?" Joan gazed at Gillian, her eyes probing.

"Well, it's not disturbing my sleep yet. I loved it when I tried the simulator! It was overwhelming."

"I see."

The expression on Joan's face still appeared to demand a further response, so Gillian added, "When I get further into the training, I'll be able to say more. I suppose the pressure's not fully on yet."

Joan took another sip of wine. "No pressure yet?" She repeated. "Most people in this bar are staring at you."

"Oh, yes. You're right about that, but I meant pressure from the training course. It's not been difficult for me so far."

"Ok."

As she talked, Gillian tried not to be distracted by her drink. Even though she had expected it in the one-G environment of the rim, the rapid way the liquid whirled and gushed from side to side in the glass as she tilted it still surprised her. On her first sip, the juice had surged so quickly into Gillian's mouth that she nearly choked, and almost dribbled.

"May I join you?"

They both looked up.

"Mr McWhirter," Joan said. By way of invitation, she shifted her seat to make more room.

McWhirter sat next to Joan and gazed across the table at Gillian. He had already purchased something, a large glass of amber fluid. He brazenly inspected Gillian.

"You're very young," he said.

The remark startled and discomposed Gillian. Red-faced, she glanced sideways and up at the ceiling, then down at her ridiculous drink. She was furious at McWhirter for making her feel and react like an uneasy twelve year old child.

McWhirter relented. "Well, I won't pursue that."

"What's in your glass, Mr McWhirter?" Joan asked.

"It's called 'beer'."

"I've heard of it. An Earth thing?"

Gillian remembered how Captain Xing had introduced McWhirter at the big meeting.

"What's a Trouble-maker?" she asked, as McWhirter was about to reply to Joan's question, her tone failing to hide hostility.

McWhirter, noting her unfriendly response to him, considered his answer for a moment.

"Governments get stuck, stale. So does politics in general. My job was to give them a thump every so often. I had unfettered access to information; I had complete immunity from the law so I could say what I like. And I dug and dug. I was a success; I stirred up a lot of institutions and Departments. And I downed a few people. I improved the system, in my opinion."

He paused, drank some of his beer, then added. "And that's why I ended up having a long sabbatical twenty light years away from it all - and now a bit further than that."

"So on this trip, you were finally heading home."

"I was." This time McWhirter smiled in a friendly way, attempting, Gillian thought, to relax her.

Joan asked, "Were you looking into something particular while you were in the Gliese System?"

"Just in a private capacity, yes."

"Anything remarkable?"

McWhirter took a sip from his glass and looked at her. "Yes, I think so." Then he gazed into his glass.

Gillian and Joan waited for him to complete his answer.

"Angular velocity," McWhirter said.

"Angular velocity of what?" Gillian asked.

"Our galaxy."

"That's an old issue," Joan said.

Gillian felt impatient with this irritating old man. "I never heard of it."

"He's talking about momentum pollution," Joan said. "Some people think our starships could disturb the galaxy."

McWhirter explained, "When you shift a mass as large as the Xinglong Hao without displacing an equal amount of mass in the opposite direction, you're disobeying the laws of physics. You're not playing the game. It's like moving weights on a spinning top. Eventually, it's going to be noticed. The top might start to wobble."

Gillian said, "You mean, the galaxy could fly apart?"

"Perhaps, at least our part of it," McWhirter replied. "The Orion–Cygnus arm. I understand it's not a big one, compared to the others."

"Nobody believes in momentum pollution," Joan said in a dismissive tone. "We're well below the noise level."

"Perhaps now, when there are only a few hundred starships. What's going to happen with thousands, or tens of thousands of them?"

McWhirter grinned, and Gillian wondered if he had been joking all along. She said, "You couldn't find enough Walkers to pilot so many ships."

"Perhaps that's what will save us."

Dr Morris, the ship's medical officer, and Mr Rogers, the astrophysicist, joined them with their drinks. They sat next to Gillian, opposite Joan and McWhirter.

"Is Mr Barry coming?" McWhirter asked the group.

"I contacted him," Joan replied. "He said he might."

"How is Abel, Dr Morris?"

"He's improving. Gillian should be able to speak to him next week." Dr Morris glanced at Mr Rogers. "I think our Mr Rogers would like to speak to him too."

"Of course!" Mr Rogers grinned at the Doctor, and Gillian immediately saw that their relationship was more than professional.

"Great!" Gillian said. Then she added, "Mr McWhirter here's been scaring us about angular velocity and galactic momentum pollution."

"It's nonsense," Rogers said. "Even a million starships zipping all over the place is a negligible momentum deficit for the galaxy. It's like worrying about atoms wobbling in your teeth!"

McWhirter smiled. "Well, I'm just an interested layman. I like to poke about." He changed the subject. "I understand you're well into your training, Gillian. How is it going for you?"

"It's all theory so far," Gillian replied. "But starting tomorrow I'm going to be using the simulator more often. It will be my second time. The first was with Abel."

"How are you finding the work load?"

"Good!" Gillian described how she commenced each week studying the ship's Walk systems, sensors and the navigation instrumentation displayed inside the mask. She mentioned how pulsar stars were used as navigation beacons.

Tuesday mornings were to be assigned to the study of astrophysics and the geography of the galaxy, focussing on the region beyond the Local Bubble.

"Now we're here, it's a once in a lifetime opportunity to gather information from outside the bubble!" Mr Rogers remarked.

"As long it doesn't delay us!" Joan exclaimed.

"Well, of course." It was obvious that Mr Rogers was only being polite.Gillian recognised the astrophysicist's excitement. She guess that this experience could boost him professionally, if he ever got back home.

On Tuesday afternoons, Gillian was to study Newtonian mechanics for planetary-scale navigation, relevant to the techniques of Starship departure and arrival, with Mr Dryen.

As they discussed her study of the Newtonian world, Mr Dryen and Mr Barry arrived. After they had seated themselves, and exchanged greetings, Joan said to them, "We've been discussing Gillian's training. It seems to be going to plan - what do you think, Mr Dryen?"

"Quite well," Dryen replied. "Gillian has a real talent for her new role." He smiled cautiously at her.

Gillian blushed.

Mr Barry drank only coffee. He looked sharply at Dryen. "I hope the theoretical work has been trimmed to a minimum?"

"Of course," Dryen replied. "Gillian's almost completed it.We've made a deliberate overlap with the practical phase: simulated Walking."

Mr Rogers added, "We're still mapping the region surrounding us, to incorporate it into a new simulation for Gillian."

Wednesdays were allocated to review and consolidation, and preparation for simulator work the following morning. Gillian was to take simulated Walks inside what Mr Rogers called "conventional space", which meant the bubble. But as soon as practicable, she was to move on to a simulated environment that was as close as possible to that of their current location. Thursday afternoons would be devoted to analysing the simulations, and debriefing meetings, if feasible, with Abel Yegg.

"How realistic is this simulation?" Mr Barry asked.

"It's as real as piloting the ship live!" Dryen replied. "What Gillian will experience while she's training will be identical to her experience when she's Walking live."

"Except that she can't wreck us, I assume."

"Well, no. But even live, she'll be under close supervision."

Fridays would be light, concerned with planning the details of the following week's work. Weekends were for relaxation, unless the committee considered that Gillian was not making enough progress.

The program was always subject to the availability of Abel Yegg for consultation. When these windows of opportunity opened, Gillian was expected to have a store of questions ready, which she was to develop throughout the course of her training. So far, a meeting had not occurred.

Mr McWhirter listened to the discussion of Gillian's training without comment. When it finished, he said, "I'm glad to hear you're making good progress, Ms Berry." He glanced at the Executive Officer. "I wonder if I might be allowed to attend a few of the simulator sessions?"

Joan replied, "I suppose that's ok. Gillian?"

Gillian was gratified to be asked. She replied, "I don't mind. But Mr Dryen must agree first. Maybe you'll have to get the Captain's approval too."

Dryen said, "I'm happy for Mr McWhirter to attend. That'll do. We don't need to ask Captain Xing."

Mr McWhirter nodded, gazing at Gillian. She had wondered if Captain Xing had been suspicious of her on her first meeting with him. Now she wondered if McWhirter might be a problem for her. His gaze disturbed her.

There was a pause in the conversation. Then Mr Barry asked, "Gillian, are you going to get us home?"

Gillian didn't hesitate. "Of course!" she said, smiling, feeling happy.

But as everyone gazed at her, she surprised herself by thinking: "Where is Home?"