Inside the jam-packed Senate Judiciary Committee hearing room, Jim Comey’s blunt words set off audible squalls of shock: “The president chose to defame me.” Wow, murmured the press. “Those were lies, plain and simple.” Uhnnn, gasped the tiny group of civilians seated in the back of the room.

Comey’s words, and those of the 17 senators questioning him, gushed out for three and a half hours Thursday morning. There were discussions of an awkward White House dinner, Russian cyber-mischief, and Thomas Becket. Yet the most significant moments were about words that couldn’t be said publicly, and things that weren’t done—and both turned the heat of the investigation directly onto Attorney General Jeff Sessions.

Video: Trump's Administration Ties to Russia

Sessions has been tangled up in this mess since nearly its beginning. While serving as a prominent Trump campaign surrogate, Sessions met twice with Russian Ambassador Sergey Kislyak—meetings he failed to disclose on a security clearance form when Trump nominated Sessions to become A.G., later explaining it as a benign oversight. Still, that failure eventually forced Sessions to recuse himself from the Justice Department’s investigation of possible links between the Trump campaign and Russian operatives. (Just how recused Sessions really is came into question in May, however, when he wrote a letter recommending Comey’s firing.)

Even so, Sessions had cannily managed to stay on the periphery of the scandal—until yesterday. Comey was quizzed by California Senator Kamala Harris, who is becoming the breakout Democratic star of the intelligence committee’s hearings. Harris wanted to know more about the conversation in which Comey pleaded with Sessions to keep Trump from interfering with the F.B.I. ”You write [in Comey’s prepared statement] that he did not reply,” Harris said, in the deceptively casual tone that made her a highly-successful prosecutor in San Francisco. “What did he do, if anything? Did he just look at you? Was there a pause for a moment?”

“His body language gave me the sense, like, ‘What am I going to do?’” Comey said, adding a slight shrug in imitation of Sesssion’s non-reaction reaction. “He didn’t say anything.”

That was bad enough—that Sessions left Comey twisting in the bureaucratic wind, a unprotected target of Trump’s continuing wheedling. But Comey, responding to a question from Oregon Democrat Ron Wyden, also teased a potentially damning new revelation: “We were aware of facts that I can’t discuss in an open setting that would make [Sessions’s] continued engagement in a Russia-related investigation problematic.” Several hours later, NBC broke the news that Comey told the intelligence committee members, in a private session, that Sessions may have had a third undisclosed meeting with Kislyak.