The Yellow Crayon

Context is everything

Mr Sabin is called out of blissful retirement to search for his missing wife, Lucille, Countess of Something or Other. It turns out she is somehow wrapped up with a pan-national Royalist secret society of frightening power and influence, much like the Nihilists who put an end to Mr. Sabin's plans in the last book. Why these Royalists didn't show up to protect him from the Nihilists is never discussed.

Like I said, readable and interesting to watch Mr. Sabin control himself and walk with such dignity and aristocratic bearing and tact, even as he plots to save his own life and reunite with his beloved Lucille.