The Resurrectionists (2007)

From the publisher's website:

They say an infamous old vampire is buried in an overgrown old cemetery outside the city. This nefarious bloodsucker was some kind of cult leader back in his nights. Stole mystic secrets from the Sanctified and the Acolytes alike and eventually went into hiding - in torpor - back in the ’30s or ’40s. But his hiding spot was lost, even by his own cult... until tonight.

You’ve got the only known clues to his whereabouts, a sealed box containing some thing of his that’ll supposedly wake him up, and one night to find his grave, dig him up and bring him back to the city. Get to it. Tonight, you’re the Resurrectionists.