Okay, so, I'm pretty sure I will start with Obi Wan crashing onto Tatooine one way or another. He will have been pursuing an enemy across the galaxy, maybe an assassin targeting Sen. Organa, who opposes the creation of a military. After he is shot down he will then encounter a series of challenges. He will encounter some while in the dessert at night with only moonlight (some great visuals possible here). Once he stumbles into Mos Eisely at daybreak his luck doesn't improve and we find out exactly why he thinkgs Mos Eisely is such a hive of scum and villainy.

Though I must admit, I kind of like this idea of it being quite a pleasant and developing city so that when Obi Wan calls it scummy later on, we're like "huh?!" and then we see why.

Anyhow, he is found by Anakin. Obi Wan senses his strength with the Force and convinces Anakin to help him get back to Alderaan.

They spend the night at Owen and Anakin's farm. Owen is annoyed by this stranger putting ideas into Anakin's head. More controversially (at least in my mind) is having Owen accompany them to try to keep Anakin out of trouble. (What do you all think, should Owen get off the farm?) Owen doesn't mind staying longer on Alderaan after he meets Beru Whitesun. And Anakin becomes equally smitten with...her sister.