What do you think was Bartimaeus's greatest mistake in the series?
It's kind of hard to find one, because Bartimaeus is a spotless kind of djinni, but he has to have a made a big mistake at one point.
As for Nathaniel...his life was a parade of mistakes.
But I think it was when he sent Bartimaeus out on the mission that ended up in his turning into slime. That was a huge mistake. And one of the worst.

I think it was when he was careless and accidently led Lovelace's djini to Nathaniel's master's house. If he had been more careful, they might not have died. But then it wouldn't have been such a great book.

Nathaniel's greatest mistake I think was not taking the amulet off Kitty cos he would have had a better chance to survive. He should have made Kitty go far far away and take tha Amulet for himself, that way he wouldn't have the huge wound in my side and he may have been able to escape.

yup, probably both the above answer's. that was a big one of barti's...he got people killed after all (it never occured to me before that one, nat didn't really blame him for it did he? strange, i supposed if it had occured to nat at the time they wouldn't have ahd the relationship they did.)

and nat, i dunno whether it was that one, nat made a lot and he probably made one worse i've just goota think about it properly.

the best thing to give to kitty is the boots not the amulet. so she can run away faster, after that it will works like zibraz's theory up there

Nathanial's biggest mistake was not trusting Bartimaeus all that time. They would've made a better team if Nathanial treated him more like Ptolemy had.

Nat's worst mistake was letting Barti find out his name. We wouldn't have a book if that hadn't have happened.