Near the end of Empire Strikes Back, Darth Vader has a big proposal for Luke:
"Luke, you can destroy the Emperor. He has foreseen this. It is your destiny! Join me, and together, we can rule the galaxy as father and son! Come with me. It is the only way."
Is Vader really intentioned to destroy the Emperor with the help of his son, or is he just trying to lure Luke into the dark side using a proposal that might sound light-side oriented to him (destroy evil, bring back peace...)?
Of course I don't mean he is already a good guy at this point, but does he really have a personal plan against his master, to take his place and have Luke as his apprentice? Is he even showing a little bit of fatherly love? Or is it all a lie?