10 Buffy The Vampire Slayer And Angel Plots That Were Never Resolved
7. Demon NAZIs
In Angel's first season, the audience are introduced to a group of Demon Supremacists named The Scourge. Their entire reason for being is purification and destruction of all humanity/half-breed demons. Doyle, it is revealed, has a connection to this group - in that he is absolutely terrified of them.
They are fanatics and, as such, both Angel and Doyle know that to fight them may prove to be impossible. Their plot when Angel encounters them is to use The Beacon - a device that will burn anything it touches to dust.
In typical Angel fashion, he prepares to sacrifice himself to destroy the device - only to be knocked down by Doyle, who sacrifices himself heroically to destroy it. At this point, the Scourge leave.
They are not destroyed and they are still out there. Later in the third season, they are mentioned in passing as potential threats to Connor, proving that Angel Investigations know that they are still a threat. However, they are never seen again.
Someone should probably deal with them at some point!