I’m nearing the end of the second book of “A Song of Ice and Fire” by George R.R. Martin. Exactly who was behind the death of Joffrey is a little muddled. I’d like to submit for consideration that Varys and Illyrio Mopatis were the main orchestrators of his downfall.
Consider this: Petyr Baelish returns from courting Lysa Arryn after Stannis’ host is broken outside of King’s Landing. Once Sansa is put aside by Joffrey, she meets up with Ser Dontos in the godswood. It is then that he gives her the hair net of amethysts with at least one stone that is actually the crystallized “Strangler” poison. He tells her that it is “vengeance for her father”, so Dontos knows what he’s giving her, and what it is to be used for.
At this time, house Tyrell has bound itself to house Lannister. Mace has taken a seat on the Small Council. Loras is a new-made member of the Kingsguard. Margaery is betrothed to Joffrey in much the same way that Sansa was; but they have been away from King’s Landing pretty much the whole time Joffrey has been king and don’t know that he’s “a monster”.
So we know that Littlefinger had a hand in the death of Joffrey, and he claims that the Queen of Thorns (Lady Olenna, Mace’s mother) actually did the deed. We saw her mess with Sansa’s hairnet, so that makes sense.
So why would Littlefinger want Jof dead? I don’t think it was his idea. We’ve established that house Tyrell didn’t have reason to want him dead at the time the hairnet was given, so it’s not their idea either.
So who would want Jof dead?
We know that Stannis wants all of the pretender kings dead, and that includes Jof, whom he holds (correctly) to be the incestuous spawn of Jamie and Cersei. Later in the series he calls for R’hllor to kill them all (and they start to drop, one by one). I’m not saying R’hllor didn’t have anything to do with the death of Jof, but the workings of a god are different than the machinations of men.
Tyrion and Sansa were out of the loop; and Tyrion has said plenty of times that he wouldn’t kill his own blood (though the best of intentions are thwarted when he finds out Jamie’s secret).
Across the Narrow Sea, however, Daenerys Targaryen has hatched her dragons. Illyrio has sent Ser Barristan Selmy and three ships to bring her back to him.
Now we’ve seen the Spider and Illyrio speaking in King’s Landing (while Arya was lost). Remember that Varys “serves the realm”. I think he wants to bring the Targaryens back into power. Consider that, while Varys came to the small council with news that Dany was pregnant, they have received no word of her dragons – news of which has spread far and wide. Varys was planning civil war to weaken the realm so that the Targaryens might return to power.
So Varys may have had some secret on Petyr (as he does on everyone). He gave Littlefinger the hairnet, and Littlefinger gave it to Sansa, all before the Queen of Thorns was on the scene. He may have connected Petyr with the Queen of Thorns as well, so she could be the delivery method for the plan already in place.
Varys will also not have Stannis sit the Iron Throne, since he’s cavorting with the red woman. Varys knows that Stannis is the rightful heir of Robert, but Robert was the usurper after all. The true heir of the seven kingdoms is Dany. And he means to see her crowned.