Milverton blackmails Mary, exploiting her dalliance in antigovernment activities as a student. Sherlock decides to sneak into Milverton's estate to steal his evidence, but even that act was anticipated. Sherlock finds that he is not the only trespasser.
This is what it is to be unassailable!
Das bedeutet es,
¡Esto es lo que significa
ser inexpugnable!
Je suis pour ainsi dire
armé jusqu’aux dents.
Isso é inatacável!
Вот что называется
«быть во всеоружии»!