Her latest plan to cleanse Italy of the Borgias is to get the black plague into the Vatican. There is a great storyline about how her plan was almost diverted. Cesare comes upon the young Cardinal carrying a box from Caterina with a peace proposal for the Pope. Unbeknownst to Cesare and the Cardinal, the box also contains the plague. But Cesare tells the Cardinal to burn the box, knowing that it can contain no sincere peace proposal from Caterina, because she doesn't want peace. And the Cardinal almost burns the box, but at the last minute can't first resist opening it to read the proposal - and, well, we'll no doubt see the deadly results of this in weeks to come.
The other most enjoyable thread concerned Jews from Constantinople seeking to establish a community in Rome. Given that the Turks recently took over the city, changing its state religion from Eastern Christian to Islamic, this apparently seemed like a good idea. But Rodrigo has a price - he'd like a priceless relic from Istanbul, as he startes to make ready his plans to celebrate the coming of the year 1500. The Jewish delegation shows up with the Spear of Longinus, aka the Holy Lance, said to have pieced Christ. Here the history depicted on the television series gets a little murky - in our history, the Turks sent the spear to Rodrigo's predecessor in 1492.
What is historically correct and shown in this episode of The Borgias is that there were doubts about the spear's authenticity. Rodrigo of course is no fool, and in a fine scene we learn that he doesn't really care whether the spear is authentic - all that counts is what people believe it to be. Machiavelli was in last week's episode not this one, but he would have concurred completely with the preeminence of belief over reality in shaping public opinion.
The spear, by the way, exists in the Vatican to this very day, but the Church makes no claim now about its authenticity.
See also The Borgias Season 3 Premiere: "Blade's Breath" ... The Borgias 3.2: Going Both Ways ... The Borgias 3.4: Incest and Debauchery ... The Borgias 3.5: Normal Love and Lampreys
And see also The Borgias Season 2 Sneak Preview