在幽暗的山谷中，魔鬼之足的传说悄然流传，令人心生畏惧与好奇。深海之战

　　Whilst in Cornwall Holmes is approached by the local vicar to determine how Brenda Tregennis died whilst sitting in a room, playing cards with her two brothers, who were struck down with dementia as a result. The trail leads to an African adventurer and a deadly root known as the Devil's Foot.