The Mysterious Benedict Society and the Prisoner's Dilemma by Trenton Lee Stewart

This is the third in the Mysterious Benedict Society series.  In this one the 4 children, Reynie, Kate, Sticky and Constance are confined to Mr. Benedict's home for their own safety.  Mr. Curtain is still on the loose, and Mr. Benedict and his team fear he is making plans to steel The Whisperer, the mass brainwashing device the children' captured from him in the earlier adventures.  When Mr. Curtain finally makes his move, the children are caught up in the intrigue and danger. They have to use all of their old talents and even some new ones to foil Mr. Curtain's diabolical plan. This was a pretty good ending to the trilogy.  All the loose ends were tied up neatly, and we gain some new insights into the character of the different children, and even Mr. Curtain himself.  I was a little disappointed that there was no new villain in the story.  I thought the interaction with Mr. Curtain had gotten pretty played out in the first two books.  Still, those who liked the first two books are likely to enjoy this thrilling conclusion. (391 p.)