So Kash n Grab is back, which means more Ian and Mickey. I've always found their relationship dynamic to be extremely interesting, and other than Fiona, Ian is overall the most compelling character. When Ian figured out that Mickey is selling drugs on the side out of the Kash n Grab, the tension and following explosive argument that gets perfectly supported by the Holy Fever song "Guided Missiles, Misguided Men" - makes the scene a great set up for some future conflict.
I think the show has set this up to go either way - Ian could help Mickey get his life together and then Mickey will move on, or Mickey will slip deeper down the drug hole and burn out totally. Either way, I don't see it ending well between them, but I really like seeing how their characters develop off of each other.