I remembered a use of sorcery. On casting a spell, I reached out to the Orb, drawing the power from that bond, and shaped it into a protection against a spell of freezing that an assassin was discourteous enough to aim at my heart.
And yet, when I reach out here, there is no Orb. And, though my memory of the theory is incomplete, having been more preoccupied with a defense than in considering the nature of sorcery at the time, I suspect it is not something I could perform a service for Ophiuchus to receive, as it would be like asking for the Furnace to light our dorm.
So, I wonder, how, exactly, one draws power from another source.