Is it just me that thought for just a second that Cercei somehow managed to manipulate Jaime, persuaded him to be a part of her evil plan to stage a prison break for Tyrion, which lead him to Tywin, basically letting him kill their father, then while trying to escape, either the guards or Cercei herself kills Tyrion.
Then, Cerceoi would get exactly what she wanted. Tyrion dead, and Tywin out of the way so she would not be forced to marry that guy.
I swear, up until i saw Tyrion get into that boat and flee, i thought that was going to happen.
