It's Dressing-up Day at the Nursery and everyone is very excited. Archie drops round all the costumes for the children, and then dashes off to get his own costume ready - but he will not tell Miss Hoolie what it will be...It's a secret...Find out whether or not Archie manages to persuade PC Plum to dress up properly, what Archie's fancy dress costume is and how he makes it (with a little help from his friends), in this fantastic new Balamory adventure.