When Luke and Leia- and the Empire- are ten years old, an Imperial garrison is posted on Tatooine. It is small and of little effect but nonetheless Obi-Wan immediately (quietly) begins gathering resources so that not a year later he and the twins depart for a new life as owners and crew of a small freighter. The children weep bitterly to be parted from their friends, from the Larses, from the gentle eopies that have been with them their entire short lives. Well, Luke merely weeps: Leia, it must be said, rages. But both emotions are understandable and pass soon enough.
A small independent trader can make its way in the Rim easily enough, though less lucratively than someone who sought out illegal cargo; in this as in everything the Force is with them. Luke fashions scraps into extenders so his small hands and feet can reach every control in the cockpit; he flies with as much skill and far more glee than Ben. Leia insists on accompanying him on every negotiation, and proves eerily talented at ferreting out the weak points of any opposition.
By the time the twins are twelve they are well-settled into their new life. Obi-Wan's hair goes from bleached sun-red back to auburn, while Leia shoots up three inches and Luke two. On the second day of a three-day hyperspace transit, the twins wake and stumble into the galley to find their guardian seated cross-legged on the ground with three small packages lined up in front of him. His solemn mood infects them immediately and they kneel across from him, scrubbing the last sleep out of their eyes.
"Father?" Luke says softly, and Obi-Wan opens his eyes. His expression is stern but his eyes smile as he unwraps the first bundle.
The children gasp as a shining blue crystal is revealed, and Leia reaches for it before snatching her hand back with effort. He opens all three packages and leaves the gems lined up on the floor, blue, green, blue. They sing softly in the Force and Luke and Leia stare. "In the days of the Order," he says wistfully, "You would know so much by now. You would have so much by now. You would be chosen by a Master whom the Force finds suitable to you in skill and temperament, who would teach you with the support of ten thousand other Jedi behind them." He reaches out as if to touch the green crystal but lets his hand fall on his knee. "This is all I have to give you."
Luke, sweet stubborn Luke, reaches over the crystals as if they aren't there and holds Obi-Wan's work-worn hand in his own. "We live free, and we have each other. What more does a child of the desert need?" Leia folds her arms and nods once, firmly.
Anakin's and Padme's eyes, in small open faces. But now more than anything he sees Luke's eyes, Leia's eyes, and he finds it in himself to smile again. "Well, if you don't need anything more than should we not make lightsabers, then?"
Luke snatches his hand back as if burnt and the twins stare wide-eyed at the crystals. "...really?!"
"Yes, really," he teases, and sits back on his heels to gesture at the gems between them. His, Qui-Gon's, Anakin's. "We will build them together."
"Yes, Father, please!" Leia crows, and Luke nods so vigorously his over-long hair whips like a dragon's tail.
"You know," Obi-Wan says gently, "In the context of being my apprentices...you should probably call me 'Master'."
"Why?" they say together, and he gives the question due consideration. 'Because it's tradition' is not something he falls back on, these days.
"It's a sign of respect, from student to teacher. A sign of humility, of willingness to be taught. I called Qui-Gon Master when I was his Padawan, but even after becoming a master in my own right I still called the others of the same rank 'Master'."
Leia hums thoughtfully, but Luke looks unhappy. "I..." he trailed off.
"Yes?" Obi-Wan prods. "Becoming my apprentice doesn't suddenly make you stop being my child. I've not known reticence to be one of your faults, young Luke."
The boy folds his hands together in unconscious imitation and makes himself meet his father's eyes. "I just, I don't like it. It's what the slaves have to say."
Obi-Wan nods. "I see. Do you think that I will begin treating you like a slave if I make you call me 'Master'?"
"Of course not!" Luke cries indignantly, as passionate in his defense as though he's been insulted by some outsider.
"Then do you think saying it will make you feel like a slave?"
Luke opens his mouth...then closes it with a shrug. "Maybe?"
"Hmm. I hear and understand you." Obi-Wan folds down a little to meet the young one's downturned eyes. "I will make you a bargain. If after some time calling me 'Master' you find it makes you feel like property rather than protege, you may stick to calling me 'Uncle' or 'Father'. Does that seem fair?"
The clouds flee from Luke's face swiftly, and Obi-Wan thanks the Force that his melancholy moods rarely lingered. "Yes, Fa-" he stops and makes a face. "Yes, Master."
"We can't call you that around strangers, anyway," Leia says importantly. "It would be conspicuous."
"Indeed it would, my young apprentice," he says seriously, and gestures to the nearly-forgotten gems. "Now, children. Choose one that calls to you, and we will begin."
Luke chooses Qui-Gon's crystal after a bare moment of consideration. Leia's hand shoots straight to the one that used to sit at the heart of Obi-Wan's blade. With mixed joy and sorrow, Obi-Wan takes up the crystal once carried by his first apprentice, and bows to the twins. "Well then. Shall we begin?"
"Yes, Master!" they chorus.