This is a summation of episode 10 of the Landscape season 3.
Our heroes continue through the depths of Arcimen, looking for the prison cells housing the two remaining chromatic dragons Ounjerul and Frichadar. They traverse the massive lava shaft and enter a new hallway that leads them to an immense wall inscribed with draconic and arcane runes. Tophat's understands that these runes are a huge assortment of magical traps, and magical reinforcements to keep the wall super strong.
Seeing no alternative, Mac rips into the wall, attempting to destroy it from the outside. He withstands the constant energy attacks of the triggered traps, and eventual takes a large chunk out of the wall, forming a space just big enough for Johann and Tophat to squeeze through.
On the other side, a deep rumbling of steady breathing is interrupted by sniffing and smelling sounds. Ounjerul comes forward and growls at Johann "You smell familiar, you smell like the thief who stole my hoard!" With that the powerful blue dragon unleashes several bolts of lightning that drop Johann to the ground. The adventurers burst the rest of the way through, and Zanos attempts to placate Ounjerul, while Mac fights Ounjerul over Johann. The dragon wants the elf dead, regardless of the state of allegiance, and Mac wants Ounjerul dead, no arguements.
The rest of the group is staggered as Mac and Ounjerul leap into a ferocious duel once again. Zanos knocks Mac out of the way, and Ounjerul rushes through the opening, attempting to escape. Mac chases him down, staggering the dragon just before he takes flight into the lava shaft. The two behemoths grapple and bite at each other's necks with dagger length teeth, and they tumble into the shaft. Ounjerul tries to break Mac's grip, but the behir takes the dragon down with him. They both crash into the ground, impaling themselves on the spikey rocks jutting out of the lava. It takes mere moments for their bodies to burn up and melt into the flowing magma.