After the disappearance of Rowan Pike, Elias, Ava, and Cross leave the safety of Elias's home and enter a forest that shouldn't exist.

Following a mysterious map, they discover Blackthorn Station—an abandoned radio facility hidden deep within the woods. But the station isn't as abandoned as it appears.

Old equipment begins operating by itself. Forgotten recordings reveal voices from decades ago, and a telephone that has been waiting since 1959 begins to ring.

As Elias explores the station, he discovers evidence that someone has been expecting him for a very long time.

Then the impossible happens.

A voice claiming to be an older version of Elias contacts him through the telephone, warning him about a hidden organisation known as the Keepers.

But the greatest discovery comes when ...