Bob Mueller is famously nonchalant amid life’s toughest moments. Much of that public calm stems from the fact that he’s a Magnificent Bastard and, specifically, the lessons of December 11, 1968. That day, then Second Lieutenant Mueller’s squad—part of the Second Platoon, Hotel Company, Second Battalion, Fourth Marine Regiment, the so-called “Magnificent Bastards”—was on patrol in Quang Tri Province when they came under heavy fire from as many as 200 North Vietnamese troops. They almost immediately began to take casualties.

Mueller organized a defensive perimeter and moved among his Marines, encouraging them to return fire; they fought for hours. At one point, Mueller led a fire team into enemy territory to retrieve a mortally wounded comrade. The rest of his unit survived, and he received a Bronze Star, with Valor, for his actions and leadership that day.

That day wasn’t Bob Mueller’s first time in combat, and it wouldn’t be his last. It wouldn’t even necessarily be his most consequential: Four months later, he was shot through the leg by an AK-47.

The time in Vietnam, though, gave him a hard-won perspective on the bureaucratic fights where he’d spend most of the rest of his career. He considers himself lucky to have survived Vietnam—and his life of public service ever since stems, in part, from that gratitude. His college classmate David Hackett never got the chance to come home, and he speaks regularly of Hackett’s sacrifice.

Even in Mueller’s toughest moments stateside—the months after 9/11, when he was FBI director, and the 2004 hospital showdown that brought him and Jim Comey eyeball to eyeball with the Bush administration—he’s evinced a certain calm amid Washington’s slings and arrows. As FBI director, even facing the daily fears of terrorism, spy plots, and cyberattacks, he used to joke, “I’m getting a lot more sleep now than I ever did in Vietnam.”

Still, you have to wonder how well Mueller is sleeping these days. It’s hard to imagine that he has faced a more challenging—or more potentially consequential—week than this past one, which has seen a steady series of attacks from the Trump administration and congressional Republicans on both his own investigation and the two institutions that he devoted almost his entire life to serving, the FBI and the Justice Department.

So let’s do a quick review of recent developments in Washington and then consider a question that has yet to get a thorough airing in the coverage of the Russia investigation and its attendant sideshows: What would happen to the investigation if Mueller were to be fired?

First, the recent barrage of developments. It’s hard to keep the hits straight; they’ve come so quickly and we’ve grown so desensitized to major, Earth-moving news stories coming and going ephemerally in the Trump Age. Just in the past 10 days, we’ve seen news that Mueller’s team has interviewed the sitting attorney general, Jeff Sessions, as well as the former FBI director Jim Comey, and begun to talk to the White House about interviewing the president himself—all signs that Mueller’s efforts are reaching a critical moment.

Then there was the news that last summer, in June, President Trump ordered White House counsel Don McGahn to fire Mueller as special counsel—a power that doesn’t technically belong to McGahn—and that McGahn resisted, saying that he’d resign rather than begin to implement the order, a powerful sign that the president’s own lawyer saw a corrupt intent behind the president’s direction.

On Capitol Hill, we’ve borne witness to a fantastical pas de deux between congressmembers Devin Nunes and Adam Schiff, the top Republican and top Democrat respectively on the House Intelligence Committee, as Nunes—who last year breathlessly reported that he uncovered evidence of “deep state” malfeasance against President Trump and rushed to the White House to brief the president, only to later admit that his evidence itself came from the White House, an incident that so compromised his own integrity that he was forced to the sidelines of the Russia investigation—now claims to have singlehandedly uncovered a vast government conspiracy underway at the FBI and the Justice Department.