It is shown in the flashback that Klaus and young Marcel first meet in 1820.
Davina is introduced in this episode.
Josh is introduced in this episode.
Similar to how the pilot was told from Klaus' perspective, and Always and Forever was told from Elijah's perspective, this episode was told from Rebekah's point of view.
This was the second episode to feature flashbacks. It was also the first time in the series that back-to-back flashbacks have occurred over two episodes.