Instructions
Travel east until you reach the sign with a potion painted on it. Go northwest until you reach the next area.
Cast the Lumos spell for light, and look for red mushrooms. Follow the mushroom path east, west, south and finally north to get to the next area.
Go to the center of the new area. This will trigger a scene where Hedwig, Harry's owl, finds something and four mushroom enemies attack Harry. Defeat them all to make a potion appear.
Collect the potion to trigger an explosion that clears a nearby path of a rock. Go back the way you came to get to the beginning of the stage.
Tap on the object in the middle of the area with the stylus to use the potion. Jump on the tree stump that appears. Use the potion on the object next to it to make another tree stump appear.
Jump on the new tree stump and then jump over the river. Follow the path on the other side until Harry reaches a monster. Cast an Incendio spell at his body to defeat him.
Continue on the path until you reach a bulb. Use the Incendio spell to make all the nearby plants wither. This will clear a path to the next area. Travel to the new area to encounter the unicorn and trigger a level-ending scene.