I warned you to keep out of the nursery, Professor.
4 seconds sound clip from the Dimension X - Almost Human by Robert Bloch classic radio drama series episode.
You can hear this line at 00:10:27 in the radio play.
Quote context
[...]
- Now, Junior, write on the blackboard: 'My name is Junior.'
- People are evil. Evil must be destroyed.
- The professor is evil. The professor must be...
- I warned you to keep out of the nursery, Professor.
- Go away.
- Junior. You don't even remember me, Junior?
[...]