After the second hour (and now 20% of the way through the series), I think I see where the series is going.
Dracula and Van Helsing have a plan to take down the Order of the Dragon. However, Jonathan Harker and Mina Murray are unforeseen complications in that plan, and Mina especially could be the plan's destruction as Dracula puts his need for love ahead of his desire for vengeance. With his relationship with Mina on shaky ground, Jonathan will investigate further into Alexander Grayson's past, which will lead to his discovery that Grayson is actually a vampire. Jonathan will give this knowledge to the Order of the Dragon because he sees it as the only way to save Mina from Dracula's clutches. With his identity exposed, his business interests under attack, and his love for Mina possibly spurned, Dracula will go over the edge, forcing his former ally Van Helsing to destroy him.
I'm not sure, though, if the Order of the Dragon will survive.