There are several plots in seasons 4 and 5 of Big Love that, if someone had told me about them after the season 2 finale, I'd have thought they were demented on pulling a prank.

The winning plot for me is: Lois and Frank get involved in an illegal international bird smuggling ring, get kidnapped and held hostage by cultists in Mexico, and that the situation is resolved by Bill infiltrating an armed compound like a secret agent and then being rescued in turn by Lois (an elderly woman) effortlessly chopping off someones arm with a machete.

I would never believe this was a Big Love storyline if you had told me after season 2.

Runner ups would be Sarah kidnapping an Indian baby or Bill thinking he could keep his polygamy a secret while running for statewide office even though the office of the First Lady, the FBI, the state prosecutors office, and hundreds if not thousands of people in Juniper Creek knew about it already.