The plot of Horn of the Abyss covers the setting of the original Heroes of Might and Magic III and unfolds in parallel with the events of the Armageddon's Blade add-on. The developers have planned the release of a trilogy of campaigns, the plot of which is based on the Horn of the Abyss artifact. In the current version of Horn of the Abyss, three campaigns are available, connected by a common story. Horn of the Abyss adds many new playable and decorative objects to the adventure map in Heroes III. One of the game objects, the Cannon Yard, allows you to purchase a cannon - a fighting machine from the forge of the new city of Quay. A series of seven objects called warehouses was introduced, when visiting which the player receives a certain type of resource every week (unlike the already existing weekly generators, the number and type of resource for which are always different). The add-on expanded the number of creature storages in which the hero fights with the guards in order to obtain resources, artifacts or warriors. In addition to new art and gameplay elements, the creators of Horn of the Abyss have added a variety of duplicates of old objects on the adventure map, mostly those that fit better in certain environments (for example, an icy underworld gate in a snowy landscape). Many objects, new and old, received their counterparts on the water landscape, including: the garrison, the seer's hut, the tavern, the teleporter, the magical shrines, the school of magicians. Three new landscapes have been added to the game-specific landscapes that have a special impact on the gameplay. Under the Jolly Roger The campaign tells the story of Captain Jeremy Albatros, a young, brash and self-confident pirate from the kingdom of Regna, whose beloved ship, the Black Unicorn, was wrecked on the islands between Nigon and Eothol. Sea storm Storm of the Seas continues the plot of the first campaign. Jeremy Albatross, heading south, decides to explore the island of Evermorne on his way. There, he meets a group of female hydromancers led by Kasmetra, with whom Jeremy later becomes romantically involved. Horn of the Abyss The third campaign completes the story arc related to the Horn of the Abyss artifact. Jeremy Albatross and his brother Beadley Roberts realized that Kasmetra was using them to get the Horn of the Abyss herself.