“Really, lying is Eugene’s superpower,” McDermitt told EW in an interview about the scene. “He knows what he has to do to convince someone of something.”
He did it first with Abraham Ford (Michael Cudlitz), whom he convinced he was a scientist who could reverse the plague if only he could be escorted to Washington D.C. Then he did it again to get in the good graces of Negan (Jeffrey Dean Morgan), by whose side he stayed until the strongman’s fortunes changed. Now, McDermitt says, he does it with Mercer.
Eugene’s story isn’t entirely a lie, but he changes just enough details to keep his friends and community safe. “He gives just enough truth so that Mercer is satisfied, but holds back on other parts,” McDermitt said.
McDermitt believes this kind of manipulation of authority figures comes naturally to Eugene. He’s skilled at setting himself up to be sympathetic and believable to cops, soldiers, people in power, especially because it’s unlikely they’ll see him as a threat. So even while on the outside Eugene is apparently on the verge of a breakdown, McDermitt says that internally, “He’s able to kind of breathe calmly and think through everything he needs to say to this guy in order to get to the other side.”