[first lines]
Jack: What are your legs?
Archy Hamilton: Springs. Steel springs.
Jack: What are they going to do?
Archy Hamilton: Hurl me down the track.
Jack: How fast can you run?
Archy Hamilton: As fast as a leopard.
Jack: How fast are you going to run?
Archy Hamilton: As fast as a leopard!
Jack: Then let's see you do it!