After the loss of his foster parents, Clark Kent leaves his home to take the train to Metropolis.
5 seconds sound clip from Superman (1948) - Depths Of The Earth (Chapter 2).
You can hear this line at 00:00:54.537 in the Blu-ray version of the episode.
Quote context
[...]
- This looks like a job for Superman.
- Can even Superman save this train from destruction?
- What will happen to Clark Kent when he arrives in Metropolis?
- Don't miss Depths of the Earth, the second exciting chapter of Superman at this theater next week.
- After the loss of his foster parents, Clark Kent leaves his home to take the train to Metropolis.
- At the depot he learns that a broken rail has been discovered nearby.
- And as the station agent tries desperately to flag the train...
- Let's get out of here and see what happened.
- That's all I can tell you, miss.
[...]