So Louis’ emotional connection to Lestat, and the fact that it wasn’t really visible in IWTV.

The really short answer is that I believe in Louis’ love for Lestat so much that I can’t quite pinpoint the evidence for it! I think it’s from reading further books and seeing Louis from other ppls’ POV, who can describe his love better than he might be able to admit. 

“Louis, the watcher, the patient one, was there on account of love pure and simple. The two had found each other only last night, and theirs had been an extraordinary reunion. Louis would go where Lestat led him. Louis would perish if Lestat perished.” – Khayman, Queen of the Damned.

TL;DR: You gonna have to read The Vampire Lestat to get that connection.

These are actually pretty appropriate here:

So, yes, I think you’re somewhat right when you say that in book!IWTV and movie!IWTV, it seems like the only feelings Louis has for Lestat are:

• a “range from hatred 
• to disinterest, 
• to pity, 
• with no real love besides the initial wonder.”

Louis is baffled by a lot of the things Lestat does in IWTV, he disagrees with Lestat’s philosophy (which is unclear in IWTV in both versions), and until Claudia rebels against their maker, Louis stays with Lestat because YES, he is still fascinated with him, he doesn’t know of any other vampires, and he’s sure he can pull more of the mysteries of life out of Lestat about vampiring, and his place in the scheme of things (whether vampires work for God or Satan is a big question).

^At the end of IWTV, Louis does meet up with a very incapacitated Lestat. Lestat says in the next book that this scene never happened. 

Whether they met like this or not, Louis clearly is “empty” at the end of IWTV, and he wants to find Lestat, but how’s he going to do that? Check the Yellow Pages? It would be like trying to find a needle in a haystack.

IWTV is like a Batsignal from Louis to Lestat to call him out of wherever he’s hiding. Some of the story is embellished (or maybe even invented) to paint Lestat as a bizarre antagonist. This is all to get him ANGRY ENOUGH to rise up out of hiding and FIND LOUIS. Whether to retaliate physically, and finally end Louis’ misery, or correct the record by putting out HIS side of the story, and everything he couldn’t tell Louis during IWTV.

Which is exactly what The Vampire Lestat is, and that’s why you need to read it ❤