Suspicion was just suspicion. Mousse had no intention of investigating the mystery of whether "Pluton" Silvers Rayleigh was dead or alive. First, time would eventually reveal the truth. Second, whether Rayleigh lived or died had no substantial impact on the current Charlotte Family. Why go out of his way?
What did surprise Mousse slightly, and make him take things more seriously, was that Marine Admiral Sengoku had managed to drive "Pluton" Rayleigh, who was currently at his peak, into a desperate situation:
"Rayleigh could still fight the then-Marine Admiral Kizaru to a draw after he got old! Looks like I really underestimated this future Fleet Admiral, who had always presented himself as a 'strategist general'! Maybe his Combat Power isn't below Garp's at all! I just don't know whether he's naturally this strong, or whether the Human-Human Fruit: Great Buddha Form is simply that powerful."
If the news of Rayleigh's death was frightening but unimportant, then the news that One Piece Roger had turned himself in—though the newspapers claimed he had been captured, the BIG Pirates' intelligence capabilities made it easy to learn the truth—was more than merely frightening.
Previously, this One Piece had unexpectedly disbanded his pirate crew and vanished without a trace, leaving the entire world baffled. Yet that had instead further tied down the World Government's and Navy's forces. A large reason the Navy had yet to retaliate despite Charlotte Linlin's earlier provocations was precisely because of this.
But now Roger had actually turned himself in? What the hell was this?
Had the One Piece who roamed the seas suddenly realized his sins were unforgivable?
How could that be possible?
But no matter the reason, Roger's surrender was already an indisputable fact.
Although they had once been enemies of the Roger Pirates, even Charlotte Linlin acknowledged this