The fact Hackett was impersonating him suggests the Spider Lady, doesn't it?
3 seconds sound clip from Superman (1948) - Between Two Fire (Chapter 10).
You can hear this line at 00:03:17.847 in the Blu-ray version of the episode.
Quote context
[...]
- Hackett and the other man tried to wreck the Reducer Ray before they left.
- But Superman got there in time, or so Clark tells me.
- When I came to, I was in the car with Clark.
- How did you get there so fast?
- You certainly left here fast enough.
- Now, have you any idea where Graham is?
- The fact Hackett was impersonating him suggests the Spider Lady, doesn't it?
- The same familiar problem: finding her.
- I've sent Jimmy out to university to follow up on it.
- Now, you two get busy on your stories.
- I'll take care of that car for you.
[...]