"Undo" is a blue instant spell from the Magic: The Gathering Starter 1999 set, classified as an Unknown rarity. It allows a player to return a target creature to its owner's hand, providing strategic utility in gameplay. Currently valued at $0.35, it appeals to collectors seeking cards from early sets, though its low market value reflects its more niche role in competitive play and casual decks. Grading and sales data indicate limited demand among collectors.