After the Great Zapfish, Inkopolis' primary power supply, is stolen, Cap'n Cuttlefish employs a Splatoon of Inklings to travel to the Octarians' secret underground base and retrieve it. Players assume the role of Agent 3 of the New Squidbeak Splatoon and traverse the treacherous landscape of Octo Valley in order to reclaim various lost Zapfish, Sunken Scrolls, and Power Eggs.

After the Great Zapfish, Inkopolis' primary power supply, is stolen, Cap'n Cuttlefish employs a Splatoon of Inklings to travel to the Octarians' secret underground base and retrieve it. Players assume the role of Agent 3 of the New Squidbeak Splatoon and traverse the treacherous landscape of Octo Valley in order to reclaim various lost Zapfish, Sunken Scrolls, and Power Eggs.