After an Avengers mission that went horribly wrong in Lagos, Nigeria results in a terrible toll in collateral damage, the U.S. Secretary of State (William Hurt) calls the team of superheroes on the carpet. He proceeds to chew them out for behaving like vigilantes with unchecked power, and then makes them agree to be supervised in the future by a United Nations panel.

While Iron Man (Robert Downey, Jr.) is willing to submit to the Anti-Hero Registration Act, Captain America (Chris Evans) is much more suspicious of these Sokovia Accords that were ratified by 117 nations. As a result, the Avengers have split into factions that takes sides as to whether or not they should abide by the regulations in the Sokovia Accords.

What ensues is a visually captivating battle in which the former allies fight each other instead of resolving their differences civilly.

Among those siding with Iron Man are Black Widow (Scarlett Johansson), War Machine (Don Cheadle), Black Panther (Chadwick Boseman), Vision (Paul Bettany), and Spider-Man (Tom Holland). Captain America’s freedom lovers include Winter Soldier (Sebastian Stan), Falcon (Anthony Mackie), Hawkeye (Jeremy Renner), Scarlet Witch (Elizabeth Olsen), and Ant-Man (Paul Rudd),

Fans of the series are delighted to see so many of their favorite superheroes together in the same episode. Regrettably, that is both the primary strength and weakness of this 13th movie in the Marvel Cinematic Universe series. Co-directors Anthony and Joe Russo (Captain America: Winter Soldier) have cluttered the screen by introducing and then failing to develop over a score of prominent characters.

It’s too bad that they couldn’t come up with anything more interesting for the Agents of the S.H.I.E.L.D. confederacy to do besides battling each other. After 2½ hours the eye-popping special effects tend to get a little tedious once the wow factor wears off.

Fair (*). Rated PG-13 for extended sequences of violence, action, and mayhem. In English, German, Russian, Romanian, and Hausa with subtitles. Running time: 146 minutes. Distributor: Walt Disney Pictures.