Rex investigates funny situations at the city's museum in his latest adventure. The third book in a series filled with laughter for readers aged 7 and up, by an award-winning author and illustrator. Rex is eager for his first trip to the museum. But wait, could it be... bones? Dinosaur bones? It turns out that museums can be scary places. And now, something or someone is causing a stir around the place, and it's up to Rex, Sandra, and the gang to find out who it is. Can Rex successfully disguise himself as a new security guard? How can he help his latest unexpected friend, an Ancient Egyptian mummy? And most importantly, can he organize the most wonderful sleepover at the museum in sleepover history? Highly illustrated throughout and packed with laughs, this is perfect for fans of The Bolds, Dogman, and Bunny vs Monkey.