Stannis is getting annoyed that the Watch have not chosen a new commander yet. He's also pretty interested in Sam killing an Other with dragonglass, and luckily he has a supply of it on Dragonstone. Stannis shows Sam and Aemon his magic glowing sword, and for some reason Aemon is suspicious because it only glows and isn't hot. Melisandre is confusing because she seems to be simultaneously wrong (about Stannis being the chosen one of some prophecy), fraudulent (I'm sure a lot of the fire visions are suggestive, and she gives off a self-serving vibe), and correct (she does have magical powers -- though they're definitely more like Dark Magic with all the sacrifice and shadows). I think she's basically Wormtounge and Stannis is Theoden. Which makes Maester Aemon Gandalf.
Sam doesn't want Janos Slynt in charge and decides that if he can convince Mallister or Pyke to back the other then that might be averted, so he goes to have a word. Only he radically overstretches himself and ends up, more or less accidentally, pulling some Varys/Littlefinger style tricks and, through a series of lies, getting them to vote for Jon as well.
But Jon is going to be lord of Winterfell! Sam what have you done? Just when things were starting to look neat and tidy, you've gone and made it all complicated! I'm pretty sure Jon won't thank you, either. Oh dear, oh dear.
