Marvel's first movie theater return after two years is becoming a smashing hit. Marvel Cinematic Universe's Phase Four officially kicks off with "Black Widow," Natasha Romanoff's own solo film.

Based on the "Black Widow" reviews so far, the film is action-packed, exhilarating, and just as spy-movie-esque as the "James Bond" and "Mission Impossible" films.

'Black Widow' Plot and Spoilers

Fans will now have answers to what happened in Budapest. Among other unanswered Avengers questions, this movie is just jam-packed with action and thrill.

How "Black Widow" fits in the MCU timeline is it picks right up where "Captain America Civil War" left off, Comicbook explained. Natasha (Scarlett Johansson) is on the run and finds herself unexpectedly reuniting with her past.

It isn't a complete origin story, but it does explain a lot about Nat as a hero and as a person.

Before we proceed, be warned, there will be spoilers.

The movie begins with an introduction to young Nat's life and her "family" of Russian intelligence agents. You have Alexei Shostakov (David Harbour) and Melina Vostokoff (Rachel Weisz) who play parental figures to a young Nat and Yelena.

We get to see Alexei's goofy, lovable, yet flawed, fatherly nature and Melina's strong and as-nurturing-as-you-can-get-as-a-Russian-spy motherly approach.

The family needs to make a hasty exit and fly to Cuba. Alexei feels relief knowing he can now let Red Guardian, a delightful antithesis to Captain America, back into action. But General Dreykov looks far more interested in Natasha who is fiercely protective of her little sister, Hollywood Reporter noted.

Cutting to 21 years later, Nat's on the run.Yelena (Florence Pugh) deflected from Dreykov's ranks and removed a tracking device planted under her skin. She gets away with a case of vials containing the antidote to Drekov's chemical compound designed to inhibit free will that he uses for other Black Widows in training.

In Budapest, Nat gets reacquainted with Yelena and they both outrun a bunch of Dreykov's deadly soldiers. Nat finds out that the Red Room still is in operation. Her "parents" reenter the picture as well.

During all of this, Yelena's deadpan humor is a perfect complement to Natasha's cold and brooding exterior. Fans also get to see a lovely contrast of Nat's "found family" in the Avengers and her dysfunctional childhood "family" of Russian spies.

Of course there's an epic take-down of the man behind the Black Widow program.

Both Pugh and Johansson work perfectly together on-screen and both give wonderful depth and complexity to their characters. It touches on vulnerable childhood wounds, resilient sisterhood, and the strength women hold.

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'Black Widow' Reviews and Reactions

The movie directed by Cate Shortland and written by "Thor: Ragnarok" co-writer Eric Pearson from Jac Schaeffer and Ned Benson's story is two  hours and 14 minutes long.

As Cnet reporter Sean Keane puts it, it's "Bourne and Bond at his best." Fans also call the movie an "epic spy thriller" and have welcomed Florence Pugh into the MCU with open arms.

Meanwhile, per Comicbook, the only real flaw of the film is its villains who are quite forgettable when compared to other villains in the MCU.

Despite not going in the same vein as the weird themes of "Loki" and "WandaVision," this movie in all its action-packed glory is still very much MCU and is a wonderful cinematic beginning to Phase Four.

Where to Watch MCU's 'Black Widow'

"Black Widow" will be in theaters starting July 9.

Disney Plus subscribers with Premier Access can also watch the film on the same day as the global premier. Premier Access costs $30 on top of the $8 monthly subscription.

You can also watch Marvel's TV shows "WandaVision," "The Falcon and the Winter Soldier," and "Loki"

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