Silk Hearts are a special and rare upgrade that can be obtained in Hollow Knight: Silksong to bolster Hornet's Silk Skills. Many of her abilities — including the healing Bind — require Silk to use, which is stored in a large spool that grows with each successful attack. A Silk Heart will automatically regenerate one notch of Silk on Hornet's Spool when all Silk is consumed, and you can find 3 Silk Hearts during your exploration. Silk Heart 1Location: The MarrowRequired Abilities: Silk SpearThe first Silk Heart is awarded to you after defeating the Bell Beast at the top of The Marrow region. Here you'll find the Silk Heart to claim as your own.