Now, old friend, it's time to get back on The Riddler's trail.
7 seconds sound clip from Batman (1966) - When the Rat's Away the Mice Will Play (S1E12) TV Series.
You can hear this line at 00:04:16 in the Blu-ray version of the movie.
Quote context
[...]
- While they dragged us down here, some of the web-like material tore away from my hand and waist.
- I just barely managed to get the cutting torch out of my utility belt.
- You burned the armature and short-circuited the power.
- Golly, Batman, the utility belt saves again.
- Now, old friend, it's time to get back on The Riddler's trail.
- The following morning at the wallowing place of the evil river rats.
[...]