His friend, Sarah, dropped into the chair opposite him, sliding a stack of books onto the table. She blew a stray lock of hair out of her face. "You're doing it again, aren't you? The 'Time Theory'?"
Marcus, however, was not suffocating. He was calculating.
" Chapter Seven: The Lost Sister " at approximately 45 minutes.
But Marcus was staring at his notebook. The numbers seemed to vibrate on the page.