The Abyssal Maw
Azeroth's native elementals wreaked havoc across the world while they were under the influence of the Old Gods.
To keep Azeroth safe from these threats, the titans imprisoned the Old Gods underground and banished the savage elementals to the titan-constructed Elemental Plane, a secure dominion where the elementals could dwell without harming Azeroth.
Four domains were created within this primordial realm to serve as ideal environments for each type of elemental. For ages since, the elementals of air, water, earth, and fire have engaged in endless strife with each other, waging titanic battles in the confines of their realm. One of the Elemental Plane's domains, a vast ocean known as the Abyssal Maw, is home to the water elementals. Legend says that Neptulon the Tidehunter, the powerful being who rules over the aquatic realm, possesses a potent weapon that allows its owner to control the very seas of Azeroth. Thus far, the artifact has remained secure inside the water elementals' domain... but that will soon change.
Within Deepholm, the domain of the earth elementals, the malefic Dragon Aspect Deathwing is on the verge of executing a catastrophic act: to burst forth from the Elemental Plane into Azeroth. Doing so will ravage the surface of the world and breach the barrier that separates Azeroth from the elementals' realm. Whether Neptulon and his subjects have entered into an alliance with Deathwing remains unknown. Regardless, if Deathwing's actions create an opening into the Abyssal Maw, nefarious and honorable factions alike will seek out the fabled weapon carried by Neptulon. Whoever secures the artifact will have control over the world's seas, a power that perhaps no one, not even members of the Horde or the Alliance, should possess.