Neptune's Trident is a powerful magical artifact forged by the Wizard Neptune, the first king of Atlantis. Since his death, it has resided in the grand tower of the city. It is capable of releasing waves of energy.
When Bryant Hughes and Harper met with the Sea Hag to find merpeople, the hag agreed to help them if they retrieved the trident from Atlantis for her. During the battle with the wizards, Billie Jenkins saw the trident in the same room as the Auger Shells.
When Arthur began his research to free the petrified wizards of Atlantis, the trident was placed in storage along with other magical artifacts. During his trip to the past with Violet, they learned that the trident was able to free the petrified wizard if it was wielded by a wizard that could control the earth.