The Fury of the Lord of the Sea

From publisher blurb: Long has an elemental sect of dragonkin sought to free the dreaded Isonade, fury of the deep. Should the leviathan come, all but those sworn to its service shall drown beneath the waves. Written for PCs of levels 16-20. Written using monsters from the Midgard Bestiary for 4th Edition D&D, this short adventure offers a mix of tactical combat and problem-solving, as the PCs must thwart that ritual before one of the great horrors rises from the depths.