Survivor count: 39,556

This episode does away with a standard recap and instead features a series overview with a unique textual prologue:

This has all happened before
And it will happen again

The Cylons were
Created by Man

They rebelled

Then they vanished

Forty years later
They came back

They evolved

50,298 Human survivors

Hunted by the Cylons

Eleven models are known

One was sacrificed

This episode marks the return of Ellen Tigh.

The numbering of the Cylon models, while admittedly random on part of the producers, is evidently relevant to their creation. Number One was the first created and named John. There was indeed a Number Seven model, named Daniel.

Very shortly after this episode aired, fan speculation ran rampant that Daniel/Number Seven was tied to many of the then unsolved mysteries in the show, specifically that he is Kara Thrace's father. Although Ron Moore allowed such theories to flourish without commenting, this was the exception, as he felt that it had gotten out of hand (referring to it as the "Cult of Daniel") and would detract such proponents' perception of the series finale, officially debunking in his podcast for the episode "Islanded in a Stream of Stars" that the the absent Cylon has any connection to the series' answers. The character's use, as Moore explained, was to both explain the gap in the model number, as well as provide a piece of Cavil's backstory, likening it to the story of Cain and Abel.

Number Seven shares his first (if not only) human name with that of Daniel Graystone, the man who created the Cylons on the Twelve Colonies about 60 years ago, as revealed in the prequel series Caprica. In fact, although the DVD of the pilot episode had yet to be released as of this episode's airing, Graystone's name, among other details, had been circulated, which lead to some speculation about a connection between the two. In his podcast, Moore acknowledges this, but does not elaborate.

Ellen: Tell me more about this rapport you have with John.
Boomer: He's teaching me to be a better machine, to let go of my human constructs.
Ellen: What about the swirl? Has he taught you that yet?
Number One: If you'll excuse me, I have some people to kill.
Ellen: Why, John, I think you're blushing.
Number One: No, it's just the faulty blood pressure in this miserable body you've designed for me.

Tigh: You heard what he said, right? The Centurions couldn't build skinjobs, so we showed them how, then gave them resurrection. It all traces back to us.
Tyrol: No, no, no. He said we ended the first Cylon War. We bought time for humanity, right?
Tigh: The Old Man said humans had to own up to what they made, but we made the skinjobs. It's all about what we made. The destruction of the Colonies.
Tory: But the humans on Kobol made us. Go back far enough, it's always them.
Tigh: Yeah, you point a finger back far enough and some germ gets blamed for splitting in two. No. Maybe we share the guilt with the humans, but we don't get to just shove it off onto them.

Ellen: I know what you did to Daniel.
Number One: That Seven didn't thrive. Sad. And it's too bad we're not made out of something more sturdy. Metal - that might be nice.