5X08 "Kitsunegari"

This episode is a sequel to the Season 3 episode "Pusher". 
Vince Gilligan, who this time will be joined by new writer Tim Minnear
is set to thrill us all again.

When an old adversary (Robert Modell) escapes from prison custody
he decides to take revenge against Agent Mulder for what he did to him
in "Pusher".

Pusher will kill anyone who gets in his way - including Scully.

The episode begins when Mulder discovers a dead man covered in 
cerulean blue paint - covered in clues that could only lead to one man
Robert Modell (Pusher).