It is hard not to feel excited before sitting down to watch "Prince of Darkness" for the first time. That was my feeling on first watch, and with it having one of Season 3's most interesting concepts part of me knew that it would be at least a very good episode. Have often seen it deemed as one of the standouts of the early seasons and it is hard to resist such a sinister sounding episode title, the episode title of the season to grab me the most even.
"Prince of Darkness" didn't disappoint me on first viewing. On re-watches, it is one of those episodes that got better with each viewing and it more than lived up to the very high expectations set by the concept and title and exceeded them. It is one of the standouts of Season 3, in its top 3 episodes, as well as the darkest and most tense (worthy of being season finale level). And a early season episode standout, a prime example as to why it is a shame that the early seasons aren't aired enough.
Can't find anything to fault really with "Prince of Darkness". It looks professional and the camerawork is neither overblown or static. The standout being at the beginning, which was quite unsettlingly (in a good way) shot. The music has a haunting and not too melodramatic presence, while being used relatively sparingly.
The acting is great, shining especially in the exchanges between Michael Moriarty, Richard Brooks and Steven Hill (also three at the top of their game). Paul Sorvino, in his last major/lead appearance (his last ever being a brief cameo in the next episode) of 'Law and Order', comes into his own here, while Carlos Sanz and Mark Margolis make the skin crawl.
Dialogue is taut yet also flows freely, one hanging on to every word without being confused or talked down to. Schiff has some brilliant lines here. It is the story where "Prince of Darkness" most stands out. It is Season 3's darkest episode and one of the darkest episodes full stop of 'Law and Order'. There is a real sense of suspenseful dread throughout, especially in the final portions, and it is full of unpredictable turns. For instance as soon as one thinks that the case is done and dusted, it is revealed that there is more to it and there is a particularly shocking change of events that leaves one floored. There is even a horrifying heart in the mouth moment where the viewer's reactions mirror exactly what the characters in question are thinking and feeling.
In summary, wonderful episode and one of the season's best, as well as an early season standout. 10/10.