Just so you know, this review is going to contain spoilers, partially because it'd be hard to explain it otherwise and partially because I hope this gives you an excuse to never see Splice and gets rid of any desire you ever had to see the movie before.
Splice starts out pretty good. It's about a genetic experiment that goes wrong and the beginning of the movie is a lot of cool science experiments and stuff. You get to know the characters fairly well and it gives you some good background for the rest of the story.
Unfortunately, the actual plot doesn't make itself apparent until about halfway through the movie.
Once the science-experiment-gone-wrong is created (which happens to be a partially human hybrid) it starts to get weird. It begins with the creators, a couple who live together(not sure if they're married), taking the creation home with them and dressing it up. See, they weren't supposed to create it and people are getting suspicious. So they sneak it out and take it home and start treating it like a child. They've named it Dren and decided that it's genetically a female. Sure, it's kinda cute at this point, look at them, they got a kid. Ain't it sweet.
Around then I stopped following. The woman creator starts getting random mood swings that we're supposed to assume are genetic. She starts taking her daddy issue anger out on Dren. Then the male creator discovers that woman creator used her own DNA in Dren because she wanted a child she comes could "control." He gets angry, they fight, woman creator cuts off Dren' s trail, which contains a dangerous spike. Man creator comes back when woman creator is gone and ends up having sex with Dren. Woman creator walks in on them and goes ballistic. She leaves, man follows soon after. They somehow make up, all is forgiven and they return to Dren to find that she's sick and dying. Dren dies, they bury her, and some dudes from the lab show up and are like "fess up and show us the thing." Creators go "she's dead bro, go dig her up yourself."
But it doesn't stop there. Then something swoops out of the sky and grabs one of the lab guys. The other three follow and see that it's some sort of Dren incarnate. Other lab guy grabbed and killed (if you didn't guess, the other guy was too.) It then turns into essentially a horror movie with the two creators running from what turns out to be a male Dren. Male creator is knocked out and boy Dren pins down female creator. This is the point when I knew I really regretted watching this movie. The dialogue goes as follows:
Female: What do you want?!?!
Boy Dren: *distorted voice* Inside you...
It then starts having sex with her. Male creator stabs the thing through the chest, Dren stabs and kills the male with its tail thing, and female smashes Dren over the head with a rock, promptly kills it.
I thought the movie was over then, but then there is a flash forward. Some chick from the lab is talking to creator female, thanking her for helping them move on to the next phase. Creator chick stands up and OH SCHEIB she's pregnant.
Then it's the end, clearly open for a sequel I pray each night will never be created.
Overall, I recommend never seeing this movie. And no, I don't remember what the characters actual names were.