A better plan would be to head straight for Bart's Guide to London, since that's hugely entertaining and witty, i.e. written by me. - Jonathan Stroud

I'm Martha. And you are...?" A small snuffle, a smaller voice. "Nathaniel.

The boy did the preliminaries, sealing the circles, erecting the bonds. Now we were all subject to the rules of the summoning. But then he stopped. He did not progress. The woman looked at him furiously. "I've forgotten it," he said.

I'm only introducing it because of a small sub-clause in an Official Charge that escaped my notice a year or two back. Unfortunately the author didn't forget. Like elephants, authors are – nothing contractual escapes them.