Your books are awesome! It's amazing that here we have a chance to ask you questions about them :D
so...my question:
Let me give you an example
let's assume for a second that Bartimaeus is really evil, Nat really stupid, and Gladstone's staff is in Lovelace's collection

and let's go back to the first book

when Nat first summoned Bart, he charged him to steal the amulet from Lovelace.
But what if Bart also stole Gladstone's staff? He COULD do that, as long as he stole the amulet too.
And then let's say he somehow convinced Nat to use it, so that he possessed Nat's body. Since Nat is now
really stupid,so he would lack willpower to stop Bart from completely taking over his body. Bart could then summon
more spirits and give them NO CHARGE, so that they could do what they wanted.
And then they could take over the world! <-- that's still the example :-/ sorry... it's so long

Is that possible? <-- that's the real question
sorry if my question was weird

I think that story belongs into the misterious realm of fanfiction. You should write it.

Ok, getting right to it :D