At first, Shen Fei had taken some interest in the transfers between Singularities because of Sherlock Holmes. Unfortunately, he had never found any clues from beginning to end. This differed from Lostbelts. Travel between Lostbelts at least took place on the same planet; only the regions differed.
But Singularities were different points in time. Differences in time were undoubtedly far more difficult than differences in space. Back when Shen Fei only had a superficial understanding of magecraft, he had not seen the issue. It was only after exchanging information on Spiritron Transfer with Morgan in the Britain Lostbelt that he truly confirmed it. Sherlock Holmes was undoubtedly exceptional at solving cases, but his talent for magecraft certainly paled beside a genius like Morgan.
Even if he had not met Morgan, after hearing about the spy from the Servants in the Atlantic Lostbelt, Shen Fei would still have concluded, after some thought, that Sherlock Holmes was the likely suspect. The reason was simple. First, the ordinary Chaldea staff could be ruled out. Without any power, they could not possibly have been involved in something like this.
That made the remaining candidates simple. Mash and Ritsuka were definitely not spies. Roman was Solomon, so naturally he was not a spy either. Da Vinci had been a possibility, but before Shen Fei appeared, he had been killed. Even though he had created a smaller Da Vinci, it had been made without sufficient resources and could only exist for a limited time.
By elimination, Sherlock Holmes was naturally the most suspicious one left. As Kadoc had said, his origins were simply too suspicious. He had not been properly summoned by Chaldea.
"But at the very least, I can say this: Sherlock Holmes could never have defected. Considering all of his past achievements, his attitude,