I voted 'very good' for that. My only two gripes were that it seemed totally bizarre that Gwen pressed the button the first time for no apparent reason. It made her look really stupid - 'ooo, look, an alien device with flashy buttons, let's press them!' Later on it more carefully insinuated that the device draws you in to pressing it once activated but I think they could have played that up a bit more the first time with Gwen's initial reaction.
There was also the odd Strictly Come Dancing mention. They said they'd been watching the final and that newsreader won. The only news reader to win it was Kaplinsky in 2004. Now this means one of two things - 1. The series is set in 2004 and that is a subtly clue or 2. The writer doesn't know her SCD very well!
Those little gripes aside the rest was very good. I liked that they stuck to the psychological, especially with the so far very unsympathetic Owen. I very much liked the fact that neither Jack nor he were right or wrong - Jack was right to say there was no point in investigating the case as there is nothing they could do without evidence, but Owen was morally right about not letting the guy get away with it. Overall the whole episode was very well acted by Burn in particular. His shock after seeing and feeling what had happened to the girl was well played. I liked the way they made him be sympathetic but still a bit of a t*sser.
I was also quite surprised by some of the twists at the end. I caught on just a few moments before they did that the kid was black mailing him and I really did think that Owen was the one that was going to kill him, Gwen would stop him and all would be well...Nicely written.
I also liked that they brought flirty!Jack back for this episode too. I the gun training sequence he knew EXACTLY what he was doing and it's good to see that the little bit of a sod in him is still very much intact. It's good too that they're making Gwen's boyfriend a nice guy who she obviously really loves. No Mickey Smith this time.
The trailer for next week looks great. I know some people will say it keeps changing and doesn't settle down, but I like the different styles of episodes. And next week looks like it will give Ianto something to do - maybe even Tosh.