*3rd pov*
“I… …I can’t believe this… I could never have imagined that something so unreal could be true…” Arthur is still shocked. “Oh? Did you not return to the manor because you were assured of the fact? If you had just continued on your way home, you would have returned to your peaceful ‘reality.’ So why return? All atremble, at that.” Sebastian points out Arthur trembling. “I-If the unease I felt turned out to be something more than simple disquiet on my part… …It would become my duty to go after the yard’s carriage at once!” Arthur tells them.
“Ha ha! Professor, you are a most righteous man. You did write of your love for the knights of the middle ages in your work, so it’s to be expected. Did it not occur to you that you might not be able to return home if you learned the truth?” Ciel smirks. “Eh!?” Arthur looks terrified. “I was only joking.” Ciel said as Arthur sighs. “–Just as you surmised… …Woodley is not the culprit. At least… not in this case.” Ciel tells him. “!!” Arthur is surprised. “However, he belongs in that carriage.” Ciel states. “......What do you mean?” Arthur questions. “We shouldn’t stand here talking. Let’s see to preparing elevenses or some such. Sebastian.” Ciel calls. “Yes, sir.” Sebastian bows as (Y/n) lays on Sebastian’s head.
“Allow me to show you the way.” Sebastian said to Arthur. “......” Arthur is hesitant. “You desire to know the truth, do you not? There is no need to be so terrified. We shall not eat you.”
*At the greenhouse*
“Today, I have prepared Fortnum & Mason’s Darjeeling second flush… …And Petits Fours as accompaniment.” Sebastian serves them while (Y/n) eats a pastry. “......” Arthur looks at the sweets and tea. “Nothing here is poisoned, so please do help yourself. –Well? How did you come to deduce this one was alive, professor?” Ciel questions Arthur.
“–In truth… …I was not convinced he was. I just felt vaguely ill at ease all the while, and… …I can’t really explain it too well, but he– how do I say this…? He was too perfect.” The three look at Arthur. “Both the butler Sebastian and Vicar Jeremy made me incredibly uncomfortable, but there was no room for suspicion. …They were perfection. It was all so perfect that I, on the contrary, began to find it strange.” Arthur goes into detail. “How do you mean?” Sebastian questions him. “It is impossible to prepare so completely in advance of one’s death… No, one’s ‘murder.’ The food, the owl, what you said to me– It was all too perfect. That was not the work of some mere premonition. And though Vicar Jeremy, who appeared after your death, was suspicious by all accounts, his alibi was flawless, and there was no reason to doubt him. And then there were his parting words…”
“Thank you for taking care of the young master.”
“The moment I heard those words, I realized the truth behind the unease I had been feeling… …And that all our deductions would be utterly overturned by one ‘unrealistic possibility.’”
“An unrealistic possibility?” Ciel questioned. “The possibility that the butler, Sebastian… …was not dead. Once I came to that conclusion, I could no longer contain myself…” Arthur answers. “For you to put all your faith into that one remark and return here… …I would expect no less from one for whom the young master has such high hopes.” Sebastian said. “What nonsense are you jabbering on about?” Ciel and Sebastian looked at each other. “Well? What did I do to pique you so?” Sebastian questions Arthur. “The first instance was when Lord Siemens was murdered. At that time, you simply observed us and the situation as it unfolded. You, who had responded so swiftly to the trouble that occurred at the dinner party, you understand? Now that I think about it, there must have been a reason. Moreover, you uttered not one word in the earl’s defence when he was under suspicion of murder. For a butler to fail to come to his master’s aid was just plain odd. Were you not aware? That the next murder would occur and dispel all suspicion from the earl?” Arthur questions Sebastian.
“Yes. I was indeed aware.” Sebastian confirms it. “So it was just as I–!” Arthur gets cut off. “However… ..that was not my reason for failing to defend the young master.” Sebastian informs him. “Eh?” Arthur is confused. “Hmph. I’ll bet you thought it served me right or the like, hm?” Ciel said. “Not at all? I was just shocked that while anticipating getting caught in some kind of trap, you readily succumbed to sleep with those cares on your mind.”
“N-Now please, just a minute!! Anticipating, you said…” Arthur shouts. “We knew beforehand that one of the guests was looking to harass the young master at the banquet.” Sebastian explains. “Th-That means… …you two had already predicted that this incident would take place!?” Arthur is in disbelief. “Yes. Also that Lord Siemens would likely fall victim to that plot… …And that I would be murdered as well, you see?” Sebastian tells him. “Eeh!?” Arthur stood up.
<<<<<<Rewind<<<<<
*Two days ago*
“Guh! GWAAAAH!!” Lord Siemens screams. ‘“Smash”?’ Sebastian wonders. “What is going on in there, Lord Siemens!? Lord Siemens!?” Mery-Rin bangs on the door. “Something wrong? What’s all the fuss?” Charles Grey questions as they all rush to them. “Let us kick in the door.” Sebastian kicks the door.
“KYAAAAH!! UWAAAAH!!”
“Ah, Mister Phelps!!” Woodley catches Phelps. “Excuse me! …He’s dead!!” Arthur announces as Sebastian looks around the room. ‘I do not smell blood either. –Which means… …something like a bottle of poison must be in there–’
>>>>>>Present>>>>>>
“Please wait! Why did you not mention that right away!? If you had, the earl would have been spared all that suspicion!” Arthur wants to know why Sebastian did it. “The young master himself appeared to be simply taking in the scene, so I followed his lead.” Sebastian answers. “A murder occurring under those circumstances– My first thought was that it was a sham. Alive or dead, Siemens took the poison himself, as I’d expected. The rest was as the butler said. I thought I’d have time enough to make my move after I had more evidence in hand… A better grip on the culprit’s tail, as it were…” Ciel explains. “I see… That’s why you had the butler go and add coke to the fireplaces. That made me wonder as well. There was no need to stoke the fire in a room with no occupant. Yet he was murdered while tending the fire in that particular room.” Arthur understood.
“Yes. The true meaning of his command at that time was… …’take a close look at that fireplace’– Still, I must say my master is a most merciless individual. For he ordered me to carry out that command, knowing I would be murdered if I went snooping around that fireplace.” Sebastian holds (Y/n). “Well, I never imagined it would all play out exactly as I had thought up to that point.” Ciel said. “As you’d thought?” Arthur is confused.
<<<<<Rewind<<<<<
“Yes… I was killed that night.”
Sebastian walks to Lord Siemens’s room and goes to the fireplace. “To ‘make sure there is enough coke to keep fires going through the night’... was it?” Sebastian gets to work on the fireplace.
“It was neither God nor fate.”
Sebastian spots glass shards.
“Following the scenario upon which my master had decided… …with the timing my master has fixed…”
Sebastian put the glass shards together to show two different small bottles.
“...By the one whom my master wished to have play the role of villain was I murdered. At the hands of the one who had come only to torment my master–”
“I should have known… This is–” Sebastian sees the reflection of the killer as he’s about to strike Sebastian.
“By Earl Grey.”

YOU ARE READING
The sleeping ash. Black Butler various x reader
AdventureBasically, the sin of sloth got transported to the world of demons, reapers, and angles by her littler brother greed. Let's see how sloth have a new eve by a demon butler. Black Butler belongs to Yana Toboso Servamp belongs to Strike Tanaka (Y/n) is...