Trump sacks FBI director: It was brazen and out of the blue - on May 9, Trump's sacking of James Comey was executed so hastily, that Comey heard the news first in a TV newsflash while on business on the west coast. The White House communications team was caught unawares, but in scrambling it seemed to get its ducks in a row - clearly Comey had to go, the message insisted, because of his mishandling of investigation of the controversial email server run by Democrat Hillary Clinton, who was Trump's 2016 election rival.

"The Russian thing": As much as they were upset with Comey, Democrats and a good many others in Washington weren't buying it - and sure enough, interviewed two days later by NBC's Lester Holt, Trump demolished the initial White House spin in a single dramatic quote - "And in fact when I decided to just do it I said to myself ... 'you know, this Russia thing with Trump and Russia is a made-up story; it's an excuse by the Democrats for having lost an election that they should've won.'"

Like an octopus, "this Russia thing" has tentacles that grasp not just at Trump's campaign, but also at the White House - on Friday, The Washington Post reported that the FBI had "identified a current [unnamed] White House official as a significant person of interest??? someone close to the president."

The investigation is looking for evidence of collusion between members of Trump's campaign and associates who might have been complicit in the Russian hacking of Democratic Party computers; they're reportedly following a money trail; and of greater personal risk for Trump, they also are investigating the extent to which the President might have attempted to derail the investigation - you know, obstruction of justice and all that.

Comey writes: In what proved to be a great tactical error, Trump tweeted on May 12: "James Comey better hope that there are no "tapes" of our conversations before he starts leaking to the press!" Widely read as a threat, it provoked searing retaliation - reports of a series of explosive memos Comey had written on all his encounters with Trump; including the sacked FBI chief's assertion that Trump had pressured him to shut down a vital part of the Russia investigation. Others memos are expected to detail Trump's unseemly demand for Comey's personal loyalty.

Rosenstein writes: Trump's attorney-general Jeff Sessions recused himself from any Justice Department work on the Russia investigation because he misled the Senate on his own meetings with Russian figures. As a result, the Russia brief is in the hands of Sessions' deputy - Rod Rosenstein. He was furious, reportedly threatening to resign, when the initial White House justification for Comey's sacking relied on a Rosenstein memo which negatively critiqued Comey's handling of the Clinton business.

Only weeks in his job, Rosenstein was widely censured for allowing himself to become a Trump pawn. But on Wednesday he put pen to paper again - a stunning, seemingly unilateral decision to appoint special counsel to run a more independent investigation of the whole "Russia thing."

Sean Spicer goes bush and there's a hand up for his job: In scrambling to spin the Comey sacking, Trump spokesman Sean Spicer extraordinarily found himself briefing reporters amid shrubbery in the White House gardens - in the dark, at night, because he insisted that the TV lights be switched off. Within days, Fox News' Kimberley Guilfoyle saw an opening and publicly pitched herself as Spicer's replacement - but if Spicer is thrown under the bus, what will Saturday Night Live's Melissa McCarthy do for the rest of her career?

Sergei Lavrov drops by: Barack Obama banned senior Russian officials from the White House in the wake of Moscow's annexation of Crimea, but on May 10 Trump welcomed the Russian foreign minister with open arms, sharing with him tightly held intelligence on ISIS, reportedly provided by Israel; and incredibly, according to a report on Friday, explaining to Lavrov, that he - Trump - was now under less pressure over "the Russia thing" because he had sacked Comey, who he described to the Russian as "crazy, a real nut job."

Robert Mueller: This is the man who Rosenstein has appointed as special counsel. A former FBI director and a close colleague and friend to both Rosenstein and Comey, Mueller is revered on both sides of politics as a savvy, detail-oriented, no-nonsense prosecutor with a proven record of standing up to presidents. His appointment should greatly worry Trump - instead, the President has brushed him off as heading "the single greatest witch hunt of a politician in American history!"

Crazy Michael Flynn: Historians will scratch their heads for decades over how and why Michael Flynn ever got on the White House payroll - he was already under investigation for his Russia connections, including receiving tens of thousands of dollars from Moscow, before Trump appointed him as his national security adviser. And Trump was aware of that investigation when he gave Flynn the gig. During last year's campaign Flynn happily tweeted alt-right nonsense about Clinton and other senior Democrats running a child sex ring; and having accepted hundreds of thousands of dollars to lobby for Turkey, he has been revealed to have made policy decisions in Turkey's favour. After just weeks in the job, Trump reluctantly sacked him after he was shown to have lied about his communications with Russia.

What happens next: Impossible to predict with any certainty, except to say that if revelations in the first four months of the Trump presidency are any indication, this investigation is a filled with dire political and legal risks for Trump, his administration and his associates. There were reports on Friday that the senior White House adviser on whom the FBI is focusing is Trump's son-in-law Jared Kushner; and there was a report during the week that apart from the handful of interactions between Trump's campaign and Moscow that have been publicly reported, there was at least another 18 such interactions.

Hanging over the whole business is a question about the tactical wisdom of Rosenstein's appointment of a special counsel.

This is how the logic goes - in pursuing the letter of the law, Mueller could come up empty-handed when it comes to crafting criminal indictments that might be proved in court. The point here is that in the US, it's often what is deemed to be legal, as opposed to illegal, that is shocking. Political stupidity is not necessarily a crime.