Risen From the Deep: A 14th Level Adventure for 5th Edition

Eons ago, before the gods and even the world came into being, there were creatures that existed in the void. Beings of chaos and unfathomable knowledge, they floated endlessly in the empty vastness that was the universe. When the Elder Gods willed the world into being, some of these creatures were trapped within it. Some found themselves trapped beneath the earth while others found themselves in the dark blackness of the the deepest oceans. Slow to rise, they slumbered for many centuries. Recently, however, one such being has awoken. Vh'etlixz, a cephalopodan monstrosity, shaped and warped over time by its time spent deep beneath the waves has risen up. It assails any who come close to its underwater lair, dragging down ships with a single swipe of its massive claws. Fearing what effect this would have on seaborne trade, the mainstay of the Lustran economy, the city's king has put out a bounty on the creature: 100,000 gp to whoever can slay the beast or seal it away forever. Many would-be adventurers, eager for the payday have rushed to Lustra in search of ships crazy enough, or driven by greed, to take them out to sea in search of the monster. Of all those who've sought it out, none have returned. 

Now, the common folk are beginning to worry as the trade ships have stopped coming. Supplies in Lustra are beginning to run low, and the island city-state is on the brink of revolution as the people demand answers from a nobility who can provide none. If no one is able to slay the beast and restore the trade routes in time, it might spell the end for Lustra and her leaders.