A brunette is dancing happily down the railroad tracks, singing to herself
"...21 ...21 ...21 ..."

After a little while, a blonde walks up to her. She observes for a minute
and then asks, "What are you doing?"

The brunette does not answer and keeps singing "...21 ...21 ...21 ..." So
the blond jumps on the tracks and follows her dancing and starts singing
"...21 ...21 ...21 ..." A little later a train comes down the tracks. The
brunette jumps off, but the blonde keeps dancing and singing to her self
and gets hit by the train.

The brunette gets back on the track and starts dancing and singing again,
"...22 ...22 ...22 ..."