Castle Glower is a very unusual place. It constantly adds rooms, towers and tunnels to itself, it ejects anyone it doesn't like, and it even selects the king. 
 It's also the pivotal setting -- and in a way, the lead character -- of "Tuesdays at the Castle," a clever and suspenseful little fantasy story about a resourceful little princess trying to save her family. The only downside is that Jessica Day George tells us hardly anything about the vital goings-on OUTSIDE the castle, but her story still has plenty of charm, magic and clever pranks. 
 When the king and queen of Castle Glower are reported dead on their return from the wizard college, Princess Celie can't believe it -- there weren't any bodies found, and the castle hasn't made her brother Rolf king. But the Council is pushing a coronation on Roth, and even invited Prince Lulath of Gath and the Vhervish Prince Khelsh. And for some reason, the castle hasn't ejected sullen, warlike Khelsh yet. 
 But the castle does show Celie a secret plot between the Council and Khelsh -- they plan to tie Rolf up in a regency, assassinate him, and make Khelsh the new king of Castle Glower. Now Celie, Rolf, their sister Lilah and the Castle must use all their cunning and knowledge to sabotage the conspirators, or they -- and the Castle -- may be the next ones assassinated. 
 "Tuesdays at the Castle" reads like a minor work of the late Diana Wynne Jones -- a sparkling fantasy world, a clever conspiracy-laden plot, and a cast of slightly quirky characters. And the central premise is full of win: what if you lived in a vast, living magical castle that had its own intelligent personality, and could scheme along with the human characters? 
 The one downside of the castlecentric plot is that there's a lot of stuff going on OUTSIDE the castle, with the wizards and Pogue searching for the king, queen and prince. But we never see any of it. 
 Fortunately, that's about the only problem. George's prose is clever, sparkling, but never condescending to her younger readers. And while the plot has a rather dark focus (royal assassinations! Murder attempts! Black magic!), she keeps it light and funny with the royal kids (with the help of the Castle and the servants) ganging up on Khelsh and the Council. Think manure in the shoes, slit seams and missing chamberpots. 
 And the characters are delightful -- Celia is clever, mischievous and also slightly naive, and her fondness for the Castle is a truly endearing trait. Lilah and Rolf round out the little trio nicely, while the childlike, dog-loving Lulath is a really delightful ally for the kids. He's simply adorable. But the most mysterious and intriguing character here is the castle itself, which has its own personality and intelligence expressed in countless subtle ways. 
 "Tuesdays at the Castle" could have used a few scenes OUTSIDE the castle, but is otherwise a truly charming, enchanting little fantasy. A delightful experience.