Anti-Sahuagin Alliance

After the party enabled negotiations between Saltmarsh and the Lizardfolk, an alliance was formed. This alliance would eventually include forces from the Five Shires as well as Locathah, Merfolk, Aquatic Elf, and Triton tribes.

The Battle

After weeks of discussions it was agreed that an attack would be mounted against the Sahuagin stronghold directly.  Initial scouting was performed on the night of 6 Yarthmont 1010, completing in the early hours of the 7th.  Intel from the raid itself and testimony from rescued prisoners, a Triton and a Locathah, cemented the alliance's resolution to eliminate the threat.
Forces were gathered and an expedition launched, camping inland a few miles up the coast from the lair, in Five Shires lands.  The camp and the attack itself were commanded by "Black Jack" Everbrand, with the separate contingents directly led by their own when the attack commenced - the humans by Tom and Will Stoutly, the Lizardfolk by Redfin.
On the night of 17 Yarthmont, a small team breached the front gate, driving into the upper, dry level of the compound.  Their mission: to trigger alerts and draw forces away from the lower levels.
With battle underway, reinforcing units of humans, Lizardfolk, and a Hin squad led by Black Jack entered the upper level, while Aquatic Elves slipped in through a hidden entrance discovered during the earlier scouting mission.  The other aquatic forces attached chains and ropes to the main gates on the lowest levels, which were harnessed to immense whales, using their great strength to rip the gates out.

Aftermath

The fighting was long and intense, with heavy casualties among the aquatic races, but ultimately resulted in the complete eradication of the Sahuagin.  While the compound had been greatly expanded by the Sahuagin, it was found that too much of the structure was now below sea level to be a suitable home for the Lizardfolk.  The Lizardfolk returned to the Blight Swamp with what little they could reclaim from the site, while Hin engineers and wizards have begun working on destroying the compound itself.