Chapters 18, 19, and 20 Summary

In Chapter 18, Clary has discovered that there are runes that allow someone to paint a picture of something, then actually hid the object in its painting. She paints a coffee cup, then puts the coffee cup into the painting. For her demonstration, she shows Jace the painting, then pulls the coffee cup out of it. Clary tells the shadowhunters that her mom painted the Mortal Cup into Madame Dorothea's Ace of Cups card. Clary's mom did this so that neither Valentine nor the Clave could find it. She knew that if Madame Dorothea didn't know that the Cup was in the card, she would never turn it over or lose it. If the Clave shows up looking for it, Dorothea would flee, with her deck of tarot cards, and likely never be heard of again.

Clary calls Simon to come get...