Sickness

The Sickness was a bacterial infection which lead to a major pandemic, killing most of the residents of Mineral Town and Forget-Me-Not Valley. It also killed many Mukumuku s.

Its origin is unknown, but it is believed to have originated in the Highlands, infecting Ezra Stanton's army. It is believed that the army ended up infecting the Mukumukus. Stanton brought the disease when he descended the Highlands, however it seems that the disease was contained as the pandemic did not begin to spread for another twenty-five years.

Later, Marlin Stanton and Gustafa travel to the Stanton Graveyard where they find the bones of Stanton's army along with fleas carrying the Sickness. Harris Moore eventually infects himself with the Sickness to spread it among the Mukumukus to end the Winter War.