[spoilers] Lucas. Just Lucas.

[Byatil]

Okay, I'm going to basically write down some notes as I'm watching... so here goes nothing!

We see Lucas in bed with Sarah at the beginning of 8.4. Lucas is staring at the ceiling, watching the rain. Sarah remarks that she's "not thinking about [her] boss when [she] should be asleep". Lucas is so preoccupied by his need for Harry's trust, it's now a contributing factor to his sleeping difficulties. We already know that he finds sleeping difficult due to nightmares, but he now seems to be suffering from insomnia due to an over-active brain - he can't stop thinking about his job. Obviously, as his job is what landed him in Russia in the first place, the link between MI5 and the nightmares (and therefore Harry and the nightmares), we can assume, is a strong one.
The fact that Lucas seems reluctant to have Sarah "vetted" seems rather significant. Almost as if he doesn't want anything to cement their relationship? I think we could interpret this as him not feeling like the relationship is 'real'... maybe in the sense that it's 'too good to be true'. Commitment issues could also be a factor, or else he's scared of losing her (Elisabeta link). The other interpretation is that he doesn't trust Harry. Presumably he would play a part in the "vetting" process, and perhaps Lucas doesn't feel comfortable with Harry knowing something personal about him.

Sarah then proceeds to ask Lucas; "What is it with you and Harry Pierce anyway?"
To which he responds with the classic line "Harry and me? It's a sexual thing."
Now, I'm assuming there's some underlying meaning to this, as well as it being a little joke on Lucas' part. Perhaps he's projecting his fears in regard to his relationship with Sarah onto his relationship with Harry? Saying "it's a sexual thing" can imply a level of intimacy, but maybe also a sense of betrayal... Sarah betrays Lucas, Harry betrays Lucas. Prophetic irony, perhaps? Or maybe I'm looking a bit too far into it

We see Darsharvin for the first time as he breaks a man's neck. Cut to Sarah tracing the cross tattoos on Lucas' back. Subtle link to the pain Darsharvin inflicted on Lucas in Russia. Lucas is asleep, which probably signifies his vulnerability with regards to Darsharvin.

Now, we cut back to a sex scene (dream?) between Lucas and Sarah, but I'm not quite sure what the purpose of this was...? Unless the writers just wanted a shallow piece of soft-porn It could be interpreted as another prophecy of Sarah's betrayal, etc etc. I'm not too sure at this point though. Seeing as it's a dream, maybe it's something to do with Lucas realising that nothing in his life will ever work out? rofl. As soon as he finds a little happiness with Sarah, Darvarshan comes along and ruins it for him.

Lucas is plagued by the nightmare of Darsharvin looking for him, calling out "Lucas North". It seems odd that he would have this nightmare as the actual events are unfolding in the immigration centre? Once again, I'm not 100% sure of the significance of this, but perhaps it's just to show how interlinked the two men's minds are. It is said that Darsharvin knows "every inch" of Lucas' mind, and I'd guess that this nightmare is supposed to illustrate that point.

...this is all before the opening credits role, so I'll leave it there for now! I'm going to watch the rest of the episode and add to this, but hopefully I will have refreshed some memories somewhat and people will be able to comment on what I've noted thusfar.