Star Trek: Deep Space Nine/Recap/S02/E19 Blood Oath

Three Klingons who were blood-brothers of Curzon Dax find Jadzia on Deep Space Nine, and she convinces them to let her go on a Roaring Rampage of Revenge with them to kill the man who murdered the Klingons' sons long ago.

This episode contains examples of:

 * Evil Albino: The villain, a Klingon only known as "The Albino".
 * I Gave My Word: Interesting variation on this with Dax, as her previous host Curzon gave his word to avenge the Klingon's death, also causing unintended Revenge By Proxy.
 * Screw the Rules I'm Doing What's Right: Jadzia's way of justifying herself to Sisko.
 * What Happened to The Mouse: Sisko promises dire consequences for Jadzia and her future in Starfleet should she disobey his orders and go after The Albino. Said consequences never take place.
 * Status Quo Is God