The familiarity and safety of the Marvel universe is flipped upside down in “Captain America: The Winter Soldier,” the best Marvel movie since “Iron Man.”

Steve Rogers, also known by his superhero alias of Captain America and played by Chris Evans, is becoming acquainted with modern-day life after being frozen since the 1940s. He keeps a notepad handy to jot down the fads and fashions of the present day. He still works for S.H.I.E.L.D., the global law enforcement initiative headed by the eye patch-wearing Nick Fury (Samuel L. Jackson), whose special personnel include the likes of Iron Man, Hulk and Thor.

It occurs to me, as I describe the background of the cinematic Marvel universe, that there is presently no movie franchise that needs as little expositional catch-up as Marvel does.

The characters and events of these Marvel movies, from all the way back in 2008’s “Iron Man” to last November’s “Thor: The Dark World,” are common knowledge. What was once — and how it does seem like a long time ago — a comic book niche is now the franchise to end all franchises. These films are seminal events; the average moviegoer is more well-versed in what a Tesseract is than a Tesla.

What makes “The Winter Soldier” one of the best Marvel films so far is that it deconstructs, in two hours, what has been established over the last six years. After a shady mission to stop terrorists on a boat, Captain America begins to question the legitimacy and loyalty of Nick and his appearances.

Enter a mysterious, bionic-armed assassin known only as The Winter Soldier, a foe who can go blow-for-blow with Captain America and his famous shield. The Winter Soldier shows up in Washington, D.C. just around the same time S.H.I.E.L.D. senior officer Alexander Pierce spearheads Project Insight, which uses the very considerable payload of three Helicarriers to preemptively take out potential threats. Think “Minority Report,” but with more militarization and death from above.

Even S.H.I.E.L.D., the paragon of virtue and stability, may be compromised from within. Can Natasha Romanoff (Scarlett Johansson) be trusted?

All the talk of espionage and smoke and mirrors makes this Marvel installment something more conspiracy thriller than escapist superhero flick. It shares more of its DNA with “The Bourne Ultimatum” than “Iron Man 2.”

Speaking of the “Bourne” franchise, the action sequences of “The Winter Soldier” are grounded more in realism than other Marvel fare. Iron Man’s suit, Hulk’s super strength and Thor’s Mjolnir hammer are substituted for a shield that almost always seems to boomerang back to its owner. The hand-to-hand combat showdowns are shot skillfully, in a way that allows the viewer to actually interpret and keep up with the flurry of motion on screen.

Everyone delivers their roles well, and returning players (Evans, Jackson, Johansson) are able to explore greater depths and nuance. Newcomer Sam Wilson (Anthony Mackie), is a war vet who counsels the post-traumatic stress disorder-stricken at the VA, and who has a trick or two up his sleeve.

That’s not to say that the movie entirely avoids some of the lesser trappings of action blockbusters. There is one eye-rolling scene where a minor character from the past is resurrected via some Hollywood science, and the villain’s philosophy is slightly askew.

Still, its multi-layered plot with action, intrigue and humor would have been enough to elevate “Captain America: The Winter Soldier” to the status of a high-quality, but safe, Marvel movie. The risks this film takes in destroying much of what has been established place it on an even higher level.

Grade: A-