Plague of Shadows is the 2nd of four stand-alone campaigns for Shovel Knight. The original game was released in 2014. Plague of Shadows followed in 2015, Specter of Torment in 2017, and King of Cards in 2019. Each features their own narrative and protagonist. Plague of Shadows happens concurrently with the original "Shovel of Hope" campaign and stars the Plague Knight.
Over the course of the game, the Plague Knight unlocks a wide range of bomb components that can be used in combination with each other, giving him a unique approach to combat and platforming.
All three add-on campaigns for Shovel Knight were made available for free to owners of the original game.