The description of 'red hair' might have inspired more hope in Mark to narrow things down if he hadn't seen several people with red hair, not to mention pink, purple and other esoteric colors wandering about.

"Fine--then let's go to your old block." Mark agreed. He didn't care to see how good his luck was, but maybe Jack's was a bit better. The man had survived all this time despite going around mocking people he didn't know in the hallways at night, after all.