A dealer gets shot and the other dealers gets spooked and leave. This leaves Walt and Jesse, with ALOT of meth just sitting there and unable to turn to cash.
They goto Saul for advice, he says he can organize a bulk purchase with a mystery dealer that nobody actually knows.
Skylar finds out that Tim is committing tax fraud and Skylar quits(or threatens to). She is really upset that he is breaking the law.
Now this is a very interesting point because if Walt tells Skylar about his secret of cooking meth, Skylar will not take it lightly and not forgive him. Tax fraud is a much smaller crime than cooking meth and that puts Walts future in trouble because he is definately going to live for longer now.