Well, we always wanted to know how and when the other members of Torchwood joined/were recruited, and this episode tells us. Including how JACK came to Torchwood, and how he came to be in charge.
Each person's tale is spun separately and done well. Of course, Gwen's story we already know, but she and Rhys do appear.
My personal favorite was Owen. Each tale explains a lot about the motivations of each character and what makes them tick, but it REALLY lets you into Owen's mind and heart.
The end, btw, with its preview of the finale, leaves you with your mouth hanging open (after you've said a few expletives probably).
I will be counting the seconds until the finale, and BBC better announce a third series soon before they get picketed. Torchwood has MORE than earned it.