Jem was having fun. She couldn't be killed, so nothing save for the complete end of the world could really hurt her, and the sight of blood and the sound of screams gave her chills of delight. This was what she lived for -- or rather, didn't live for -- and she couldn't help it if no one else thought she was sane for feeling that way! She didn't need anyone else to agree with her on this. In her mind, the Apocalypse was just wonderful.
Currently, she was playing a makeshift game of hopscotch over a corpse lying on the sidewalk. He had died with a large bottle of aspirin in his hand, and it was still there in his cold, dead fingers as he laid there, little white pills scattered all about. Poor thing probably thought it was just a horrible flu.