On the track, the band say: "A Greater Call is the link between the city and the void above. Imagine walking up to your vessel. How the excitement grabs hold of you. The feeling of uncertainty.

"Are you even going to be able to push through the atmosphere in one piece? A last breath before blast off and then we leave. The song is about how humanity is cutting its losses and leave. Its only hope lies above. Although it might not be representative of the album as a whole and Julie's involvement, it is where the journey starts."