While Li Feng was still complaining to Kreacher about the clothes, he spotted an owl bearing some sort of emblem outside his room window, carrying a letter and politely tapping on the glass with its beak.
Kreacher now knew Li Feng was not from this world and guessed he did not understand what the emblem on the owl meant. He quietly reminded him, "Master, that emblem belongs to the Post Office. It is delivering a letter to you."
Li Feng scratched his brow, slightly surprised as he guessed, "The only people I know in this world are Sirius and Lupin. Could they have gotten the Time-Turner and the information already? That was efficient."
Kreacher opened the window, took the letter, and fed the owl a few crumbs. Perhaps the Post Office owls were well trained; after merely glancing at the food in Kreacher's hand, it flapped away from the Leaky Cauldron.
However, the owl's refusal of food made Kreacher say with certainty, "Master, it really is an owl raised by the Post Office. Only their owls refuse food from anyone other than their handlers." Looking at the name "Lupin" written on the envelope, Kreacher handed the letter to Li Feng and said, "Master, your guess was correct. This is a letter from that filthy Werewolf, Lupin."
Taking the letter, Li Feng felt that habits were truly strange. After only one day, he already felt somewhat accustomed to Kreacher's constant chatter.
Ignoring Kreacher, who was still muttering curses at Lupin like a madman nearby, Li Feng unfolded the letter. After only one glance, he helplessly handed it to Kreacher. Damn it, I forgot I'm not familiar with English handwriting. I can roughly tell the letter has something to do with the Time-Turner, but I can't understand the details.
"Kreacher, translate it."