Place the white card inside the shoebox lid. Drop small spoonfuls of two or three paint colours directly onto the card in different spots: a teaspoon of each colour is enough, as the marble spreads it quickly. Do not mix the colours at this stage.

Drop one or two marbles into the lid and tilt it side to side. The marbles roll through the paint and leave looping coloured trails across the card. Children can tilt for 30 to 60 seconds; longer than that and the colours merge into a muddy middle ground. Lift the marbles out with a spoon when done.

Lift the card from the lid and set it flat on newspaper to dry for about 20 minutes. The paint layer is thin so it dries quickly.

An adult draws and cuts a haunted house silhouette from the black card: the house fills the lower third of an A4 sheet, with a pointed roof, one or two tall chimneys, a pointed turret and simple rectangular windows. It should be about 15 cm wide and 10 cm tall.

Glue the black silhouette to the lower portion of the dried marble-roll background. The colourful streaks show above and around the house as a lurid sky. Leave to dry flat for 5 minutes. The finished piece looks best viewed from a slight distance where the marble trails read as stormy clouds.