
If you want, I can call Internal Affairs,
Money Heist Season 1, Episode 11

Homeostasis refers to a system's ability
to regulate its INTERNAL environment.
The Big Bang Theory Season 6, Episode 2

At best you can say, "Hey, look, my idea
has an INTERNAL logical consistency."
The Big Bang Theory Season 1, Episode 3

The Internal Revenue Service
would strongly disagree.
The Big Bang Theory Season 2, Episode 18

Internal jugular.
Money Heist Season 1, Episode 5