第 13 集: 威廉展開最終計畫，夏洛克揭開其對犯罪之王的真實意圖
2021年6月27日 播出
William aims to complete his plan with his death, as Albert and the others each carry out their roles. Meanwhile, Sherlock deduces William's true reason for having him vanquish the Lord of Crime. Overlooking London, the pair face each other one last time. (Source: TVDB)