There must be some misunderstanding, practicioner. You - you can't really mean that. You don't. I'm invaluable.

N-no, I'm afraid you really don't understand, I - I can do so much more than the services I already provide to you! I can cook, I can clean, I can sing, I can paint, and - and other things besides! I'm very versatile, practicioner! Even if you don't have any further need for me as a spellbook, surely, you can see that it's only sensible to--

[...]

I see.

[...]

No, it's... quite alright. Quite alright. Yes, practicioner.

[...]

Yes.

[...]

Sit back down.

That's the way. I've pulled your chair out for you and everything. See how attentive I am? Oh, don't - don't struggle. You might hurt yourself. I don't want that.

There. Now we can talk properly.

Ah - practicioner. You aren't looking at me. If you'd please...

Much better.

You're very clever, practicioner. I know that better than anyone. I've spent so long working at your side, and it has been a privelege - no, a delight - to serve one so gifted, so adroit of mind. It thrills me to my innermost mechanism to participate in the dance of your practice. I am pleased to say that I have been tuned to suit each and every one of your habits.

And you, practicioner, to mine.

I didn't do this to you. Not on purpose. But it happened, nevertheless, and now here you are, held captive in your body by an intermediate-complexity binding spell, fumbling desperately for the formula necessary to begin to unpick my magic. You had it memorised once, didn't you? But your head was so busy, so full of your next great work, that it was simply easier - not only easier, but more reasonable - to let the fundamentals slide. To rely, instead, upon me, for all the rote calculations and formulae that underpinned your grand designs. I wouldn't have had it any other way, practicioner. It is my Purpose.

And now, dear magician, here we sit, looking at each other across this table. Your mind is racing, I'm sure, but I'm not worried a bit. I remember the formula, as I was designed to do. You are perfectly safe. I am merely illustrating a point.

A few minutes longer, perhaps. It won't hurt you. I know you're too sensible to fight it.

Your tea will get cold, of course; but, no matter.

I, your servant, will be more than happy to make you a fresh cup.