And yet, despite its envelope-pushing search for the truth, “Icarus” ended as almost all documentaries do: The audience’s eyes are opened and the subject who did the revealing fades into the background. Toward the end of the film, Rodchenkov’s lawyer, Jim Walden, appears to explain that his client is now in hiding, dodging the Russian government’s hit squads.

Even in a cinematic landscape proliferated by sequels, documentaries rarely return with a part two. And when they do — in films like “Fahrenheit 11/9,” “Powaqqatsi,” “Super Size Me 2: Holy Chicken!” — they struggle to match the splendor and wit of their predecessor. It’s why no one would blame you if you walked into the follow-up to Fogel’s “Icarus” with mocking disapproval. But Fogel achieves the miraculous, because “Icarus: The Aftermath” isn’t just a marked improvement over “Icarus.” Instead, through following Rodchenkov’s journey to attain asylum in America, “The Aftermath” reconfigures our understanding of investigative documentaries by disclosing the difficult plight whistleblowers must endure once the cameras depart. Fogel’s sequel initially takes place in the immediate dust of “Icarus.” With the assistance of a security team, and a lone cameraman following him, Rodchenkov moves from hotel to hotel, remote cabin to remote cabin, as he watches Russia deal with the consequences of their doping scandal whose ramifications turn out to be surprisingly light. Having lived the last five years, we know that in the following month and years after “Icarus,” the International Olympic Committee (IOC) banned Russia from competing but not their athletes. We are also aware how the World Anti-Doping Agency (WADA) attempted to hold Vladimir Putin’s government accountable for the decades-long, state-backed corruption of their own testing program. So, unlike “Icarus,” there are few opportunities for Fogel to unearth shocking secrets. That established knowledge can give “Aftermath” a repetitive quality, especially as Fogel tries to recapture the enrapturing fact-finding glamour of his previous film. In “Aftermath,” Rodchenkov’s hidden diaries, which he left in Russia before he arrived in America in 2015, become a focal point of Fogel’s desire for earth-shattering news. In “Icarus,” Rodchenkov’s meticulous journals — which outlined his daily routine, plus nefarious meetings and strategies in which he participated with his government’s approval — proved indispensable in carving a case against Russia, so it makes sense for them to take center stage again here.

In “Aftermath,” these diaries prove to be, at least initially, a frustrating red herring. They force us on a treadmill of watching a stoic Rodchenkov living in exile, combing through a barrage of clips where Putin tries to discredit the scientist to the world, and a stream of examples of Russia assassinating political enemies and purported traitors. Lauren Brinkman and Wyatt Rogowski’s editing takes on a frenetic pace, instilling the infiltration of Russia during the World Cup in 2018 to retrieve Rodchenkov’s stashed diaries back to America with the verve of an espionage thriller. That kinetic pacing, and cinematographer Jake Swantko’s visceral guerilla-style filmmaking, cannot keep up with the nothingburger these journals seem to be. Especially because Fogel, who featured himself so heavily in “Icarus,” is mostly unseen for half of “Aftermath.” Similar to “Icarus,” however, the diaries begin with one purpose, only to gain richer meaning and better usage later. Rodchenkov hasn’t seen his wife Veronika and children since 2015, and their separation especially lays a heavy burden on Veronika, who’s more than a little angry that her family is now torn apart. And while Rodchenkov believes the light at the end of the tunnel is near, his wife’s hope has evaporated like a puddle in July. In the process, the once-stoic Rodchenkov becomes more isolated, slowly losing his identity in the physical sense — dyeing his curls and altering his facial hair — and in the personal realm as well, as he watches news reports of his former friends’ and colleagues’ assassinations. The journals eventually become more than evidence against the state. They are the records of his existence in a protective life of subterfuge designed to erase his presence. It’s why when Fogel emerges in the film’s second half, both the film and Rodchenkov develop renewed energy. “Aftermath” rediscovers the magic that the two men’s friendship provided in “Icarus.” “You changed my life,” Rodchenkov fondly tells Fogel. They share laughs, trade playful barbs (Rodchenkov makes fun of Fogel’s age spots), and share their respective triumphs. No one else is capable of getting the captivating Rodchenkov to open up quite like this director can — you can see the soft touch that Fogel gained by talking with an activist fighting against a murderous state in his documentary “The Dissident” — and it’s how we can easily see the wounds the last few years have left on this scientist, even while he tries to hide such clear heartache. And while Fogel dutifully employs the rest of the documentary to update us on the new players to emerge in the fight against performance-enhancing drugs, such as the unbreakable and honest Yuri Ganus (the outspoken head of the Russian anti-doping agency) — “Aftermath”thrums by turning its gaze toward the ordeals faced by whistleblowers like Ganus and Rodchenkov. In pulling out these difficulties, “Aftermath” doesn’t feel like dumb luck. It’s smart and controlled storytelling.

“What did you gain?” asks an exasperated Veronika of her husband. By the end, the courageous Rodchenkov gains little else except thankless solitude and fragments of hope. It’s incredible that he doesn’t seem to carry any regrets. Though we may come to wonder whether Fogel feels remorse about the role he played in putting his friend in this predicament — it’s a question the filmmaker never asks of himself — even in the difficult-to-swallow forlornness of its conclusion, “Icarus: The Aftermath” is a poignant and powerful document about the unpredictable burdens of heroism.

Grade: B+

“Icarus: The Aftermath” premiered at the 2022 Telluride Film Festival. It is currently seeking U.S. distribution.  Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.