This episode is a bit 'Torchwood does Arrow'. It has a heavy focus on flashbacks involving Jack and a love interest called Angelo Colasanto, although at times it feels as though it focuses a little too much on these sequences. I would have liked to have seen the pacing in the Present Day sequences with Gwen in the car quickened up a little, rather than playing second fiddle to the story in the 1920s.

It's really cool seeing a reference to the Trickster's brigade though, something which really helps to tie the show into the rest of the Whoniverse, given that we had another member of the Trickster's brigade in Doctor Who and the Trickster himself in The Sarah Jane Adventures.

I do also like how this episode shows the ingenuity of Rex and Ester. The way they discover what is happening with Gwen and come to the rescue is very clever, and shows how valuable they are to Torchwood. And Angelo is a good character too. He is exactly the kind of person you can imagine Jack falling for.

I think Immortal Sins stands out a little bit compared to the rest of Miracle Day. There's a lot of memorable moments to the story of Jack and Angelo. Not only is it that particularly Torchwood level of tragic, but that whole scene with the mob freaking out and repeatedly murdering Jack was really cool. While less about the Miracle Day story, it feels like the sort of interesting stuff that Jack's story should be chalk full of and I do appreciate Immortal Sins for that and what it does for Jack's character more than anything.

Overall a distinct and exciting episode, best since the series opener. Introducing the time jumps and a more concise contained plot makes the show sing better. 1920s Jack Harkness, an exploration of his immortality and the way he has been mistreated by people he has put trust in is a delicious thing to watch unfold. Seeing Gwen have to turn on Jack and getting some high quality time with characters I am actually invested in, in the modern day scenes, also gives some much needed dynamism to a series which has sorely lacked interest. The sexy dialogue though. Oh my dear GAWD please NO! One of the cringiest things to ever happen in Doctor Who.