Vergen Besieged is a Chapter 2 main quest on the Iorveth path in The Witcher 2: Assassins of Kings. Geralt wakes in Philippa Eilhart’s quarters just as Henselt’s army moves on Vergen, and he joins Zoltan Chivay at the gate to help Saskia’s forces hold the town.
The defenders use an old dwarven mechanism to pour boiling oil on the attackers, but Dethmold destroys the barricade with magic and the Aedirnians fall back to the walls. Between the assaults, Geralt and Saskia check the secret Tunnels of the Founders, where they run into Kaedweni soldiers and Dethmold, guided by a traitor from Vergen. Dethmold’s spell knocks Geralt down, and Saskia saves him by turning into a dragon, revealing that her dragonslayer story was a cover for her true form.
During the third assault Iorveth arrives with reinforcements. Geralt fights his way to him, and Zoltan forces the jammed gate mechanism so the gate can be closed on the Kaedweni in the courtyard. Henselt is forced to surrender, ending the war for Upper Aedirn.
After the talks, Philippa and Saskia leave through a portal without explanation. Searching Philippa’s room, Geralt and Iorveth find a book called “Venoms and Poisons” and conclude that Philippa poisoned Saskia with a mind-controlling venom. They set off to rescue her, which leads into the final chapter.
