Krynn's Vanguard debated for quite a while before they decided that Korril wouldn't bring the fight to them, and they needed to bring the fight to Korril.
As they ventured into some cliffside caves, they felt their energy being drained by some odd source they couldn't quite snuff out. After loosing a fair amount of health and energy, they retreated for the time being. It turns out, Korril's ancient form of venom became not only airborne, but also hydrolyzed infecting both the air in the caves as well as the water under the bridge and what was in the caves as well.
Another round of deliberation occurred until Krynn's Vanguard decided to invite Korril to 'tea' the next day, and the dragon agreed allowing them safe passage down to where he laid in wait.
This is exactly what Korril wanted. An underwater fight where he had the upper hand against those who weren't adept for fighting on the ocean floor. A battle ensued the next day. Krynn's Vanguard was doing very well until the Green Dragon Highlord Salah-Khan appeared to assist in the fight, which ended up helping Korril immensely as the focus fire was now split. Even though at one point it was only Arcadius and a very hurt Big Bob standing,Krynn's Vanguard prevailed. At the end, it was Kyan Covverre's Mass Heal that turned the tide getting Arcadius and Orla back to full health while Korril was injured enough that he couldn't recover or bring down the party before perishing himself.
Needing to get back to the surface, Krynn's Vanguard took a small break before heading out back to Crossing to see what the Imperial Army was dealing with as it's probably more than just Korril attacking here.