Blood Vessel - S1-E2
Trivia: The secretive room on the ship with a dark secret is cabin no. 9. Mark Gatiss, co-writer of this series, also co-wrote another creepy BBC series called "Inside No. 9"
Other mistake: At the end, when the reflection of burned Lucy still shows her beautiful, Dracula's reflection shows him as he is seen; not old and ugly as in his usual mirror reflections.
The Rules of the Beast - S1-E1
Dracula: I'm undead, I'm not unreasonable.