Special counsel Robert Mueller’s probe into Russia and the 2016 US election is now a year old. Much about it remains hidden. We don’t know what Mr. Mueller thinks about the nature and full extent of Trump campaign connections with Russia-linked figures. We don’t know whether Mueller and his team believe President Trump intended to halt the Russia probe by firing FBI Director James Comey. We don’t know whether Mueller thinks Trump’s actions and state of mind add up to obstruction of justice – or if he believes a sitting president can be indicted for obstruction or anything else. We’re not even sure whether Mueller will make his findings public. One thing we do know: Compared with similar past efforts, Mueller has been moving relatively quickly. Below is a timeline of public actions related to his probe so far.