He didn't respond to what Luo Jin said and simply sent a message on their team channel.
YUN: [Did Holmes share any plans with you, Yan Yan?]
Noctis: [He found the situation intriguing. I told him that Jack the Ripper is our prime suspect, and he agreed. Apparently, the main reason he's on the Orient Express is that he was following a lead—one that suggested the Ripper had boarded the train. He didn't share many details yet, but it's clear he's been investigating this long before we got involved. That means he might already have crucial information we don't.]