4x7Problem Dog Episode Summary Aired: Sunday August 28, 2011
Skyler is unsure how she'll launder Walt's meth-lab earnings through the car wash successfully. Walt convinces Jesse to kill Gus and concocts a ricin poison in the lab that Jesse then hides in one of his cigarettes. Jesse hesitates and doesn't poison Gus. The cartel offers Gus an ultimatum, which he rejects. Jesse returns to the 12-step group. Hank visits Gus' restaurant with Walt Jr. and obtains Gus' fingerprints from a cup.