A Hidden Door

While playing outside one day, Mary comes across the robin, who flies around the grounds, encouraging Mary to follow him. The robin eventually comes to a stop sitting on a wall covered in ivy, which, when blown back by the breeze, reveals a hidden green door. Excitedly, Mary takes the key from her pocket and tries it in the keyhole. For the first time in ten years the door to the secret garden is open…

What new discoveries will Mary make there?