Three weeks after uncovering the secrets of Room 17, Jayden Carter and his friends finally think the mystery is over.
Then UNKNOWN sends them one more photograph.
It shows a dark hallway beneath their school—and a door marked 18.
The friends soon discover a hidden staircase, an underground control room, a forgotten archive, and records that were never supposed to be found. But Room 18 isn't simply another secret room. It's a backup for something much older.
As Jayden, Maya, Eli, Noah, and Sofia follow the clues, they uncover the story of Daniel Reyes, a student whose records mysteriously disappeared years ago. They also discover that Jayden's cousin Evan was investigating the same mystery long before they were.
Someone is still watching.
Someone is still changing records.
And someone wants the truth to stay buried.
When the group finally reaches the original archive, they discover that the mystery beneath their school is connected to something much an old route known only as Route Zero.
The door to Room 18 was only the beginning.
Now they have to find the road that started it all.