According to StarWarsNewsNet, the 10-year old Princess Leia Organa is being held prisoner in a Cantina-like establishment, and Obi-Wan seeks to rescue her.
MakingStarWars adds those details:
- Bail Organa visits Obi-Wan in his cave on Tatooine and asks him to save his adopted daughter
- Obi-Wan leaves Tatooine on a public transport and goes to a disreputable crime-ridden planet
- The Inquisitors have studied the past friendships of certain Jedi before Order 66
- The 5th Brother and the 3rd Sister have then organized the abduction of Bail’s daughter in order to lure Obi-Wan
- Obi-Wan meets Kumail Nanjiani’s character on the gangster world. This man is a contact of Bail and Obi-Wan. He guides Obi-Wan to the spice den where Leia is being held captive.
- Obi-Wan is disguised when he enters the spice den.
- Leia (apparently played by Vivien Lyra Blair) “has a lot of sassy pep”.