Hitman, Retrograde.

"Hitman, Retrograde" is a short story by crime author Stefanina Hill. An unidentified man sits in a Tokyo hotel room thinking about his former friend, Raphael, who now seeks to avenge the betrayal that resulted in his arrest. As Raphael moves closer to achieving his goal he is tailed by federal agents hoping to capture prominent members of "the organization". As the danger escalates Raphael's past is fully revealed.
Can the man that betrayed him survive the wrath of the dangerous predator he helped to create?