I've always felt a fascination about the untold stories of Biggs and Wedge, what was their role before Luke got involved, etc. And they have the coolest names!
Since there was apparently an imperial garrison right in the middle of Mos Eisley, I imagined what might happen if Biggs had an inside rebel contact there... He arranges to meet him perhaps to exchange information or discuss recruitment for the rebellion, but it turns out to be a trap. Biggs is escorted as a prisoner into the garrison but breaks free by jumping into a passing landspeeder as he is marched down a street, then is pursued through the narrow winding streets by speeder bikes, over roof tops, etc...
I started these storyboards but got too busy to finish the challenge.