The Candy Shop War Series by Brandon Mull

The first Candy Shop War by Brandon Mull introduces the reader to friends Nate, Summer, Trevor, and Pigeon as they meet Mrs. White, a magician who comes to their town and sets up what at first seems like a harmless candy shop. But soon the kids realize that Mrs. White has a sinister plan. Finding friends in Mr. Stott, a good magician, and Mr. Dart, a magical law enforcement officer, the kids set out to stop Mrs. White from succeeding in her evil scheme to take over their town. But will they be able to stop her?

In the second book, Arcade Catastrophy, the same friends are facing off with Mr. White, Mrs. White's dastardly brother before he can follow through on his own underhanded scheme to take control of their town, and ultimately the world. What has happened to Mr. Dart and Mozag, the head of magical law enforcement? Will the kids be able to find out what happened to them, let alone rescue them? In the third book Carnival Quest, the kids, Mr. Dart, and Mr. Stott are suspicious of a carnival that has come to town. There was one sibling to Mr. and Mrs. White left, Camilla White. Is it possible she's the one controlling this carnvial? And what has happened to Mozag and the Battiato brothers? How can the kids help Mr. Stott rescue them? The carnival that has come to town most certainly has something to do with it, but can the kids compete when people keep mysteriously disappearing in the carnival?