Better Call Saul

Potential avenues

• Kimmy knows that Saul's behavior is dangerous and that at some point she might be forced to testify against him. She doesn't want that and initiated the "fake" marriage so she can apply spousal/testimonial privilege. She then eventually breaks up and leaves.
• Kim gets killed by the cartel
• Kim gets paid off by someone and leaves
• Kim was a silent part of Breaking Bad, she was still with Saul but not mentioned in the entire plot. This would be strange since Saul Goodman is very vocal about his personal life. However, this is still a possibility. They might also be simply living different lives with different plots while still being married. The personal lives of key characters are not explained within Breaking Bad, unless critical to the story line. Especially their romantic lives are not clearly explored: Until today we do not know anything about Gus' partner, we also do not know whether there was more to Mike than being the trustful enforcer. Only essential romantic partners are relevant (Skylar, Jane).

Kim and Jimmy were a couple from day one. What started with a shared cigarette and playful scenarios eventually leads to actual criminal behavior. At some point she will no longer be able to accept the transformation and will listen to her inner voice. She fell in love with Jimmy even though "she could do a lot better", but falls out of love with Saul who eventually lives on the dark side. Jimmy is the one who needed Kimmy to evolve into the independent criminal lawyer that Saul embodies.