The strange transmissions are becoming harder for Elias to ignore.

What began as unexplained radio interference has developed into something far more personal. The voices coming through the static seem to know things they shouldn't—and some of them appear to belong to people who are no longer alive.

As Elias follows the trail left behind by the mysterious recordings, he discovers evidence that the Signal has been reaching into different points in time. But every answer creates another question.

With reality beginning to shift around him, Elias is forced to question his own memories. What if the past he remembers isn't the past that actually happened?

Meanwhile, Ava knows more about the Signal than she's willing to admit, and Cross begins to reveal the existence of a hidden organisation that has been monitoring the broadcas ...