Books with title Molly Maybe and the Ghost Train

Molly Maybe has a marvellous secret - she and her faithful sidekick, Waggy Burns, are the only ones who can travel to an amazing monster world which mirrors our own. Take a ride in the incredible mundervator with Molly and help her solve a crisis in Undermunder. There’s a terrible smell in Smallsbury but Molly knows that it’s not the drains! She ventures down into Undermunder and discovers three little monsters, who can’t stop pumping out pony smells in fear. They’ve lost their kite and too scared of the ghastly ghost, the Ghoulie Gumpus to get it back. Will Molly be able to show them there’s nothing to be scared of? Or is the Ghoulie Gumpus just too ghastly?