Pen on David Charlton's desk.
Words on blackboard at the end of the movie.
Conrad jumps off a bridge onto the last carriage of a train.He's then seen standing up on the first carriage then moments later on the second one , then the third, then first then the second.
In staff room when looking out the window watching the fight on the football pitch.
In classroom when teacher goes back to his desk after giving the new student a pen, and a few moments later when he was addressing Conrad.