
Internal jugular.
Money Heist Season 1, Episode 5

No, he cut open a tauntaun and used
its INTERNAL body heat to warm him up.
The Big Bang Theory Season 2, Episode 23

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

a record of the INTERNAL process
of their cognition.
Westworld Season 2, Episode 9

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