Na, das passt doch zu dem, was ich gesagt hatte.
Im Text steht zur #350:
As symbolic payment his final last job, he handed Gambit a vial containing his excised grey matter.
Als Leser der #350 erfährt man aber nicht, was in dem Fläschchen ist. Hier gibt es nochmal eine ausführlichere Beschreibung zur #350:
https://uncannyxmen.net/comics/issue...1st-series-350
Revealing a strange vial that he[Mr. Sinister] kept in an inner pocket of his suit and tossing it to Gambit, Sinister remarks it was a most peculiar fee to request, but a reasonable one, for him at least – and he trusts for LeBeau, as well. “Trust all ya want,” Gambit retorts and grabs the vial.
Worum es sich dabei handelt erfährt man erst in Gamibt (Vol.3).