Where/when

Jô Shishido is a top assassin (like he was in "Branded to Kill") that has been recruited by the mob to kill a rival mobster. Watching Jô setting up and executing this hit was pretty exciting--like watching a master at his craft. However, in a twist, after completing the job, the son of the now-dead mob boss decides on a truce with the rival mob--and to cement the merger, the son demands the death of the assassin...as well as his assistant (Jerry). Suddenly two mobs are out to kill them and it looks as if there's absolutely nothing they can do to stop this. Along the way, the duo meet up with a young lady (Chitose)--a woman whose fiancé was killed by the same mobsters trying to kill Jô and Jerry. She befriends them and tries to help them...it it's possible. All this leads to one of the best film noir/action movie endings I've seen in a long time when it's just Jô and a team of dirt-bags out for his head.

I have extracted some from one of reviews of a Japanese movie on IMDB.

I'd like to know why the relative adverb "when" is used in my example, not "where."
Thank you in advance for your help.