"The thing about runes is that once invoked, they can function as a closed system, fueling themselves until autophagy is complete. Nothing in, nothing out. Of course, the introductory rune courses don't teach cycling lines since there is typically little point in preventing re-invocation, but every rune can be adapted to cycle its current." His hands twitch upwards, as though trace runes in the air, then return to stillness, smile fading slightly. "The invocation process is somewhat different, since the goal is to create a local well within the rune rather than create a connection to your own well, but it is fairly straightforward. You could probably ask the Inscribed Thaumaturgy professor to guide you through it the first time. It is a little difficult to master through words alone." 

Jupiter listens intently, fascinated by the intricacies of runic magic. "A closed system," she muses. "Clever. And it would keep Madame Ryoko from sensing our magic." She watches the Professor's hands twitch, a pang of sympathy in her chest. His expertise is clear, even if he can no longer demonstrate.

"I could ask the Inscribed Thaumaturgy professor," she says slowly. "But wouldn't that raise suspicion? Asking about advanced techniques out of the blue?" She frowns thoughtfully. "Perhaps I could frame it as general curiosity about runic theory. Express interest in specializing, maybe." Her pale eyes search the Professor's face. "What do you think? Is there a better way to learn this skill without drawing attention?"

"You could make an attempt with just my explanation to guide you. Little harm in failing to invoke a rune. Of course, it is a tricky concept and usually learned through visualizing another's current flow. But who knows? Perhaps you are a prodigy." A flash of a grin, and then he continues. "There are also books with projections of current flow, though I don't think we have any in the public library. It may be less suspicious to ask the professor about a generalized book rather than a specific concept. You could also ask an advanced Inscribed Thaumaturgy student, if you know and trust any."

She looks to the Professor, pale eyes gleaming with determination. "I'll speak to the Inscribed Thaumaturgy professor tomorrow, then. Request some introductory texts on runic magic, maybe hint at interest in specializing." A faint smile touches her lips. "Who knows? I may even develop a genuine passion for it in the process."

He smiles back. "Ask for texts by Madame Ceratil. Her current visualisations are the most intuitive, I've found. We may make a runeweaver of you yet."