Special counsel Robert Mueller has been chosen as Time magazine’s third-place runner-up for 2018 Person of the Year — a recognition of the significance of his investigation into Russian interference in the 2016 election and possible collusion with the Trump campaign.

Time’s Person of the Year recognizes “the person or group of people who most influenced the news and the world — for better or for worse — during the past year.” Although Mueller rarely makes any public comments, his presence has loomed over American politics and foreign policy for the year.

As Time’s Brian Bennett and Tessa Berenson point out, the special counsel instead speaks through his work. The probe has indicted or gotten guilty pleas from at least 33 people and three companies since Mueller was appointed in May 2017.

On the central question of whether the Trump campaign — including the president himself — coordinated with Russia during the 2016 election, Mueller’s indictments and court filings have offered some details, but never the full picture. Yet, slowly, it seems Mueller is building a case. But to what is still stubbornly unclear.

As 2018 winds down, the special counsel’s investigation feels as if it’s entering a new stage, with a flurry of activity around some potentially key players in the investigation.

President Donald Trump has turned in his written answers to the special counsel’s questions about Russian collusion. Michael Flynn, Trump’s former national security adviser, who pleaded guilty to lying to the FBI about his contacts with Russian officials, is cooperating on at least three investigations.

Trump’s former lawyer and fixer Michael Cohen recently pleaded guilty to lying to Congress about a Trump Tower project in Moscow and is now cooperating with the special counsel. And Paul Manafort, Trump’s former campaign chair, entered into a plea deal with Mueller — and then broke it by being untruthful, according to prosecutors.

But Mueller’s investigation hasn’t been universally welcomed, and the probe itself is representative of the divided America that persisted in 2018. Depending on whom you ask, the special counsel is saving American democracy, or leading a politically motivated “witch hunt” against the president.

Trump — the second-place runner-up for Time’s 2018 Person of the Year, one ahead of Mueller — has led the charge against “the conflicted” Mueller and his band of “angry Democrats” with daily tweets and comments, often punctuated with the phrase “NO COLLUSION.”

Mueller still hasn’t answered the collusion question yet, but the investigation around it is already changing the course of American political history.