Critically analyze this line, "Are we never to get out of the Valley of Fear?"

This question, which Mrs. Douglas asks her husband, informs the reader of the cloud under which Douglas lives, and also refers to a literal valley in which the man once infiltrated the infamous Scowrers. The simple query indicates how much of a toll this situation takes on both Mr.Douglas and his wife; it also indicates how powerful the Scowrers are.