If you don't have a sense of where you're going when you put together a movie, anybody more mature than the average twelve year old is going to know it. I think that's what's wrong with 'Darklight'. Watching it, I had the unshakable impression that the actors were making up lines and situations as they went along, while the plot seemed not so much to unravel as it did fray; to sputter, rather than flow.
The special effects weren't all that hot, either. Aren't we supposed to be in the age of highly-developed CGI technology, where the creation of, say, a realistic demon (if that's not an oxymoron) on-screen almost requires nothing more outré than a software suite from Circuit City? Where nowadays what is needed most to be convincing is an actual vision, not just a vague, cartoonish idea?
And it's too bad; it's an interesting idea: Lilith, Adam's first wife, lives today, but with artificially-induced amnesia. While 'somewhat evil' herself, she is nevertheless 'kept in reserve', so to speak, by one of those secret-brotherhoods-that-last-for-millennia which has served occult fiction so well over the years, and is brought back to fight a greater evil.
At least, that's what I think is going on, but after a half-hour or so, I found myself not really caring. Even some good creepy atmosphere was not enough to save this latest 'bad babe' fantasy--particularly when the babe in question, seemingly meant to be one of those 'damaged waifs' so popular in modern fiction, comes across instead as rather mentally challenged.
If it's a cold, rainy night, and you're all sitting around, feeling a need to have some background while you play Yahtze, give it a watch. Otherwise, check out the Weather Channel.