Invisibility is a simple thing.

Brittany stood by, frowning and watching, as Mike shoved his earbuds into his ear and tried to read. Most normal people would have, of course, just left him alone, but Brittany wasn't very smart. And while Brittany wasn't too good at anything involving a book, she was very talented when it came to reading people. "Hey, Mike... what's wrong?" she asked, coming over and sitting next to him on the bench.