Elliot wakes up in Tyrell’s SUV with no sign of Tyrell. This "zero day" gap becomes a massive mystery for Season 2.
If you missed it, go back. It shows Whiterose (leader of the Dark Army) meeting with E-Corp CEO Phillip Price at a formal party, revealing they are actually in cahoots. The Soundtrack (Setting the Vibe)
The music in this episode is legendary for its "end of the world" energy:
Plays during the final montage and that ominous knock on Elliot’s door.
Played on a harp during the Whiterose/Price meeting, a haunting reference to the song allegedly played as the Titanic sank.