"So you've come into contact with it?"

"I'll answer your question when you answer mine."

"I need to know your knowledge base to explain properly."

"Assume I know nothing, then, other than it's a jewel you asked me to retrieve for you from a very magical someone else."

And he launches into an explanation of the Basic Tenets of Life Force Magic. Not, really, anything related to what the jewel does.

"This is in fact needed to understand what the jewel does, yes?" he interrupts to ask.

"That depends on what level you're trying to understand it. For a thorough understanding, it's needed."

"And for a direct, practical, superficial understanding?"

"It stores energy."

"What for?"

"Magic."

"What kinds?"

"Primarily life force magic."

"I saw the jewel. Fiddled with it a little. It wanted to burn me."

"It has its defenses against intrusion, yes."

"Okay. So can you give me a more tailored answer knowing that I did in fact see the jewel?"

"It can only be used effectively by someone of my mother's blood, it'll resist anyone else. It has - parts of her, imbued in it."

"—parts?"

"A pattern based on her lifeforce, which imbues the jewel with a limited version of her will."

"...I see. Do you suppose I could convince it to cooperate with me into fooling the Lord that I'm making progress?"

"...I could give you a fragment of my own power, but I would need to be able to trust that you wouldn't use it against me."

"Do you have a proposal for a verification method? I don't want to use it against you, but my word is not necessarily enough."

"My usual verification method is 'my wrath if you break your promise,' which doesn't really apply here," he points out. "...Only thing I can think of is a long-delay curse that I could later remove. I don't have lie-detecting magic."

"...long-delay curse could work if we had a way to verify you had actually removed it..."

"Someone with soul-sense would be able to spot it. Probably. If they were any good."