You'd think the Angel would have been foresighted enough to give us a birth-control rune, but no dice.
Cassandra ClareHe kissed each finger, and with each one of them spoken a word. Five kisses, five words. His last.
Cassandra ClareShe had fallen asleep with her head on his arm, the clockwork angel, still around her throat, resting against his shoulder just to the left of his collarbone. As she moved away, the clockwork angel slipped free and she saw to her surprise that where it had lain against his skin it had left a mark behind, no bigger than a shilling, in the shape of a pale white star.
Cassandra Clare