In the novel Dracula, why did the driver of the carriage that was taking Jonathan Harker to Dracula's castle stop and go where the blue flames were?
Suddenly, away on our left, I saw a faint flickering blue flame. The driver saw it at the same moment; he at once checked the horses, and, jumping to the ground, disappeared into the darkness. I did not know what to do, the less as the howling of the wolves grew closer; but while I wondered the driver suddenly appeared again, and without a word took his seat, and we resumed our journey.
What was he doing there exactly?