The reviews are in: ‘Avengers: Infinity War’ is not a movie for Marvel beginners

More than two months since “Black Panther” smashed all expectations about comic book films, Marvel is set to unleash its most comic book movie to date with “Avengers: Infinity War,” a crossover event the studio touts as 10 years, three phases and 18 pictures in the making.

The reviews are in, and…