'Da Vinci's Demons' spent a lot of its second season setting up Leonardo Da Vinci's trip to America, so it's going to be interesting to see how it wraps up its season now that the trip has turned out to be a dead end. It turns out that the show was saving its best episodes for last as tonight's episode was a corker. The episode opens with Leonardo at sea trying to repair the talking head, as Riario tells Leonardo to return to his art as he will return to the pope. Their ship reaches land and the two discuss that their friendship may be over with the passage of time. It seems the boys are back in Florence, and Leonardo returns to Verrocchio where he finds out that Dragonetti has been replaced and is arrested. Lorenzo's castle has been trashed, and Claire is in chains and Duke Federico in charge. In prison, Da Vinci and Nico are reunited with Vanessa, who's about to give birth, but then Leonardo is taken to be tortured, where he's kept in bondage near Carlo. The two are broken out by Zoroaster and Amerigo, and return to Verrocchio's where they meet up with Dragonetti and plot to rescue the city and castle. Leonardo plans to build a trebuchet, but in doing so Zoroaster, Dragonetti, and Vespucci are captured trying to get wood, so they go with plan B: enter through the chimney.

Lucrezia has been questioned for three days, and the questioning reveals that there are two popes and that one seeks war. The interrogator reveals that all Lucrezia wanted was to start that war, which she might have. But the son of the Sultan returns, and she's prepared... for something.

Sixtus tries to get Lorenzo to reveal where he's keeping his gold and he won't budge, but may promise it to King Ferrante to buy himself some freedom. Lorenzo kisses Ippolita, which Sixtus sees. Lorenzo goes to Ferrante, who's been killed, which puts Alfonso in charge, and Lorenzo crap out of luck.

Riario returns to the Vatican and talks to the real pope, asking for absolution, but the pope offers none because he let the fake pope kill his daughter. Regardless, Riario leaves him the keys so he can escape. Riario then goes to get penance by cutting his wrists in a lake (but someone sees him). He then wakes up in the care of "the enemies of man."

When a guard tries to rape Vanessa, Nico stands up for her, which leads the other prisoners to stand up as well, while Carlo and Leonardo make their way through the castle's chimney. Da Vinci gets there just in time to see Federico about to torture his friends. Amerigo and Zoroaster are to fight to the death, and they go at it when Da Vinci gets all the guards but Federico, who takes a secret passageway out. The two then get into a sword fight and Da Vinci wins, but Clarice gets the killing blow as she takes his other eye out along the way. Florence is freed! Party time! Everyone's going to get laid! Then Verrocchio finds Da Vinci to show him the fixed talking head, which reveals a clue where his mother (and the book is), and so Verrocchio and Da Vinci are about to take off when Leonardo's attacked by Carlo, who is a part of the enemies of man, and he also knew Da Vinci's mother. Carlo is able to weaken Leo, kill Verrocchio, and burn down his home now knowing where to find the Book of Leaves. As the house burns, Leonardo passes out.

Okay, that's more like it. Sword fights, suicides, double-crosses, gratuitous nudity, tonight's episode had it all. You have to give the writers credit, Carlo always seemed like a bad egg waiting to hatch, but they pulled the trigger on that in a way that was a smart left turn and also revealed that his role previous may or may not have been an act.

Maybe it's because the quest for the Book of Leaves in Aztec country was a cool idea, but didn't really go anywhere, this felt like an episode in the right direction, and everyone got something to do in a way that felt more natural than previous episodes. Tonight's episode felt most like a serial in the ways that this show has seemingly always wanted to be like, and was probably the most exciting and most fun of the season. Too bad next week offers the season finale.