(Read as a bedtime story to my 13 and 10 year old boys. The 10 year old give it "3 to 3.5 stars", with points off for the fighting between the siblings, go figure.) 
 A mother who mysteriously disappeared one day. A busy father who sends his children away while he conducts business. And the three children themselves, who embark on an adventure that takes them through London, and ultimately to a castle, which holds many secrets. 
 The children struggle to continually work together towards a goal; much bickering and arguing and pointless discussions abound. This part occurs between the middle child, Lucia, and her younger brother Max. I deal with a fair amount of sibling fighting in my real life, so it wasn't a pleasure to read about it. Repeatedly. Still, it did help both solidify the characters as well as lend them credibility. I completely believed their interactions, heh. 
 The older brother Otto is part of the quirky/whacked tag for this title, along with several other characters and situations the kids find themselves in. Oh yeah, and this book has one of those interactive narrators, like Pseudonymous Bosch. I like that, it is a bit different and it can lighten the mood. Though this is just once in a while. For the most part, one of the siblings (we aren't told which one, though the boys and I did guess from time to time) is the narrator. 
 The writing style is good, the storyline was fine, and I appreciated the mild oddness of it all. I didn't like the ending, (view spoiler)[ largely because it felt like such a rapid switch from the tone and pace and such of the rest of the book. It was a lot to take in, all within just a couple of chapters. The flow was disrupted, and it never recovered for me. (hide spoiler)]. Also, I found at least three typos, something that strongly bugs me in a published title. 
 Decent, not great. I don't know that I will seek out any more titles with these characters.