An (In)Compleat Atlas of the House

Crocodile Ring

Dr Scamandros gives Arthur a thin, silver ring in the shape of a crocodile, its tail in its jaws. It has bright-pink diamonds for eyes and its body is scored with lines that divide it into ten sections, each marked with a tiny engraved Roman numeral.

When Arthur wears the ring, some of these sections change from silver to gold, indicating how much he has been tainted with sorcery – once he is more than six tenths contaminated, he will no longer be able to leave the House.