The Forgotten Door (Apple Paperbacks edition) by Alexander Key

This is a mass-market vintage paperback edition of the science fiction novel 'The Forgotten Door' by Alexander Key, published under the Apple Paperbacks imprint by Scholastic Inc. The book features a softcard cover with a distinctive bright purple border that characterizes the Apple Paperbacks line from the mid-to-late 1980s. The front illustration depicts a young male character falling through a glowing, rectangular aperture into a dark, rocky environment. The title text is rendered in a stylized, bold yellow-and-white font with a slight outer glow effect. In the top right corner, the Scholastic 'apple' logo is visible alongside the ISBN (0-590-43130-7) and a price of $2.95 US / $3.95 CAN, which helps date this specific printing to the late 1980s. The physical condition of the item shows moderate wear typical for vintage children's literature, including visible corner blunting, edge wear along the spine, and minor creasing. A notable circular pink sticker is affixed to the bottom right corner, which may have been a price tag or library marking. The binding appears intact but shows typical shelf-aging. The copyright for the original text belongs to Alexander Key, first published in 1965, though this physical copy is a later reprint designed for the youth market. The printing quality is standard for mass-market paperbacks of the era, utilizing wood-pulp paper that likely shows some degree of yellowing or tanning on the interior pages.