mirror   hit by a car   character name in title   secret   piano   cell phone   mathematical equation   mathematics   blindness   policeman   clue   locked in a room   rowboat   chess   whodunit   science   reunion   mathematician   murder mystery   scientist   math whiz   trapped in a room   poor eyesight   twin sisters   math   math genius   opening titles scene   hospital   shrinking room   suicide   villain   telephone call   sister sister relationship   surprise ending   gas station   shrinking   river   suspense   tension