The Ghost of Christmas Past is after Shaggy and Scooby. You must disguise them by using the costumes present on the screen, following the statue model in the bottom left corner. Scooby and Shaggy are hiding in the cellar. Dress them up to blend in when the ghost comes by. Take the items by dragging them on the character. Some parts of the costumes can be hidden and you must click on other objects on the screen to find them. The timer tells you how much time remains until the ghost comes on screen.