NK Cell battles the Cancer Cell, who is able to shapeshift and spread into the surrounding environment. Meanwhile, U-1146 and Killer T Cell run into Cancer Cell's multiplying clones. The Cancer Cells order massive quantities of nutrients to be delivered to the apartment to greedily sustain themselves, but AE3803 feels suspicious and alerts the rest of the immune system. The original Cancer Cell wants to destroy the body for designating him to die as soon as he was born. U-1146, Killer T Cell and NK Cell are cornered and about to be killed, until the other immune cells arrive. All the Cancer Cells are wiped out, with NK Cell delivering the final blow against the original one, but he vows revenge before dying in front of U-1146.