This episode is a perfect representation of why I watch this show. Not only was it original, but to this day I have not seen another show copy this plot. Now, "Pique" is one of those episodes that you catch parts of at different times, but it takes a while before you can actually sit down and watch the entire thing. At least, that's the way it was with me. I kept catching the last three or five minutes, and, needless to say, I was very confused. However, once you watch the entire thing (as is to be expected), everything falls into place.
I actually got chills when watching this episode. Given, I've seen the entire thing about three times now and parts of it considerably more, but nothing seems to change from time to time. As a matter of fact, I had to watch it again the other day because scenes were running through my head and wouldn't stop until I did. Chad Lowe gives a chilling performance as Jason Mayberry, especially near the end when the detectives have him in interrogation. It was certainly a nice change from his previous role on ER as yet another annoying doctor who wasn't worth his salt.
The concept of piquerism, a paraphilia where a person obtains sexual gratification by stabbing, cutting, biting and otherwise piercing the skin to draw blood from his victims, is a fascinating one. The idea to use hat pins to achieve said means was a brillant move on the writers' parts.
In short, it was a great episode with a great plot to boot.