I rated this five stars a long time ago, out of pure nostalgia, without really remembering much about the book beyond "they stayed in the museum." Well, I just finished reading it out loud to my son, and I would just like to reaffirm: YES, five stars. No question. 
 The plot is so subtle, compared with so much of what is being published now! But wow these kids are individuals. Wow they talk like real humans and have a real and wonderful relationship with each other. My son described Mrs. Basil E. Frankweiler herself as "half forensic scientist, half philosopher." She's also 100% unapologetically prickly old lady, and 100% real herself. 
 It's so subtle, I was afraid my son would be bored or wouldn't get it, but he loved it. Really loved it. It was such a wonderful thing to read aloud together. These are the times he'll remember, I hope. I certainly want to hold those moments tightly in my heart.