It by Stephen King.

It by Stephen King.
is a classic horror novel first published in 1986. It’s a sprawling, multi-layered story that alternates between two timelines, focusing on a group of friends who confront a malevolent entity in their hometown of Derry, Maine.

The novel follows the Losers' Club, a group of seven children who are terrorized by a shape-shifting creature that often takes the form of Pennywise the Clown. The story spans their childhood and their adult lives, exploring how the trauma of their past continues to affect them as they return to Derry to face the evil force once again.