"After being put back to sleep and abandoned in an old museum, Slappy is brought to life by a curious girl on a school trip. Out for revenge, Slappy uses his powers to raise an army of creatures from the exhibits. But when the museum closes, Slappy and his new friends are locked inside with Arragatis, an ancient mummy with his own plan for revenge. It's dummy versus mummy as Slappy faces his most dangerous and frightening opponent yet! Can Slappy...

Jack and his younger sister take a trip in their tree house back to ancient Egypt, where they help a queen's mummy continue her voyage to the Next Life.