A threat looms in the dark, intent on utilising perihelion to further its goals. With budget cuts shuttering other organisations tailored to combat alien threats, P.R.O.B.E. alone must step out of the shadows to defend the very existence of humanity. But how will they cope? With the team struggling to get along, tensions fray. And for Azacca Dixon, P.R.O.B.E.'s newest member, things will never be the same again.