At the very end of the episode, they made it sound as if the barman had been the demon all along, but surely if the demon travelled from body to body, he'd only been infested very recently himself?

And how did the demon plan to invade Kate? I thought it had been said earlier that it could only travel from one body to the next after they'd (ahem) exchanged bodily fluids?

I recall an episode of Buffy where Cordelia made a big deal about learning for the first time that vampires can't enter a house without an invitation. Yet when Doyle explained it to her in this episode she acted as if she'd never heard it before.

For that matter, how then did Angel get into the other apartment when he discovered the girl's body and the newly infested man? Or can a vampire get into a home if there's no-one there to say 'no' (or rather, no-one there to not say 'yes')?

When the human who owns/rents/lives there dies a vampire can enter the residence.

There's a discussion topic on vampires entering in the Kitchen Sink. It may have spoilers though.

Answering your question about it all being blamed on the barman. Remember the police don't know anything about demons being involved. Kate therefore assumes, since the barman tried to kill her and that he knew all the other victims from working at the club, that he was the killer.

The killer trying to enter Kate without the *ahem* 'exchange of fluids' is a big plot hole.

Just saw episode 3 of S8 of the X-Files. The creature in it was really similar to the demon in this episode.

Make that episode 4 'Road Runners' The first two eps were shown back to back in the UK.

The creature in this episode reminds me of a Goa'uld symbiote... it even enters through the back of the neck!