When a steady parade of doubles for the intrepid heroes of Angel Investigations shows up and wants the originals dead, Angel and company know it's part of a sinister plan. But these doubles are more than just looks, they have the goods too. The team quickly finds out it's difficult to kill someone who knows you inside and out, and who thinks exactly like you do. But kill them they must, and quickly.
Dark Mirror takes a plot that's not new to the universe of Buffy and Angel. After all, Willow faced her doppelganger, even alluding to facets of her own personality the young witch hadn't known at the time. Yet, the idea of a copy of Angel, Wes, Fred, Gunn, and Lorne, trying to kill our heroes sounds intriguing.
This story is a fun romp. It takes place during the fourth season of Angel, and I found a bit of the continuity a bit off, or at least that's the way it felt to me. But as far as an interesting idea, and running with it, Dark Mirror provides an entertaining way to spend a few hours.