"Dracula's Guest" follows an Englishman (whose name is never mentioned but is presumed to be Jonathan Harker) on a visit to Munich before leaving for Transylvania. It is Walpurgis Night, and in spite of the hotelier's warning to not be late back, the young man later leaves his carriage and wanders toward the direction of an abandoned "unholy" village. As the carriage departs with the frightened and superstitious driver, a tall and thin stranger scares the horses at the crest of a hill.
After a few hours, as he reaches a desolate valley, it begins to snow; as a dark storm gathers intensity, the Englishman takes shelter in a grove of cypress and yew trees. The Englishman's location is soon illuminated by moonlight to be a cemetery, and he finds himself before a marble tomb with a large iron stake driven through the roof, the inscription reads: Countess Dolingen of Gratz / in Styria / sought and found death / 1801. Inscribed on the back of the tomb "graven in great Russian letters" is: 'The dead travel fast.' which was an ode to the fable Lenore.
The Englishman is disturbed to be in such a place on such a night and as the storm breaks anew, he is forced by pelting hail to shelter in the doorway of the tomb. As he does so, the bronze door of the tomb opens under his weight and a flash of forked lightning shows the interior - and a "beautiful woman with rounded cheeks and red lips, seemingly sleeping on a bier". The force of the following thunder peal throws the Englishman from the doorway (experienced as "being grasped as by the hand of a giant") as another lightning bolt strikes the iron spike, destroying the tomb and the now screaming woman inside.
The Englishman's troubles are not quite over, as he painfully regains his senses from the ordeal, he is repulsed by a feeling of loathing which he connects to a warm feeling in his chest and a licking at this throat. The Englishman summons courage to peek through his eyelashes and discovers a gigantic wolf with flaming eyes is attending him.
Military horsemen are the next to wake the semi-conscious man, chasing the wolf away with torches and guns. Some horsemen return to the main party and Harker after the chase, reporting that they had not found 'him' and that the Englishman's animal is "a wolf - and yet not a wolf". They also note that blood is on the ruined tomb, yet the Englishman's neck is unbloodied. "See comrades, the wolf has been lying on him and keeping his blood warm". Later, the Englishman finds his neck pained when a horseman comments on it.
When the Englishman is taken back to his hotel by the men, he is informed that it is none other than his expectant host Dracula that has alerted his employees, the horsemen, of "dangers from snow and wolves and night" in a telegram received by the hotel during the time the Englishman was away.

Question:  When did the Englishman notice that he was actually in a cemetery?
Answer: When the location was illuminated by moonlight.
Alternative answer: When the site gets illuminated in moonlight.