The biography of Marc Oberlindes, a sample character of Traveller, tells how once when his son was imprisoned he recruited a bandof mercenaries to rescue him.
In the Ravenloft setting, Rudolph van Richten went Papa Wolf on the Vistani band that kidnapped his son, and then hunted down the vampire who'd hired them to deliver the boy.
It's revealed in Van Richten's Guide to the Vistani that the originally kindly and very forgiving doctor's curse of vengeance upon that particular Vistani clan for what they did is the reason why they can never rest in one place for more than a day or two. Because with his curse that "the undead take you" as they took his son to the undead, every surviving member of the clan is forever hunted by the undead until Van Richten lifts the curse with his forgiveness.
Kill one of Sanguinius' Blood Angels (ergo: Sons) and he WILL break your spine. Likewise, if you hurt Sanguinius, the Blood Angels will tear you apart.