Act 3 is a hidden, extended portion of the story locked to most players unless they defeat Act 2's final boss using a tool ...

Unique to Hollow Knight: Silksong, crests are the foundation of how one approaches exploration, combat, and overall movement.

The Crawfather boss in Hollow Knight Silksong is an optional boss you encounter in Act 3. Reaching his lair requires a special invitation that appears in the form of Craw Summons.