It’s not hard to understand why Rotten Tomatoes scored this movie as they did now, though it’s also not worth saying that it’s a horrible movie, because it’s not the worst that’s ever come along. Thor: The Dark World, still holds that distinction, and even saying this is essentially stating that the MCU has slipped a couple of times, but has never really made a horrible movie that can’t be watched. Much like Iron Man did at the beginning of the MCU, The Eternals are changing things up as Phase 4 continues to roll along and the earth continues to be threatened from one direction or another. But what we learn in this movie, oh yes, big spoilers ahead, is that the Eternals and their masters, the Celestials, could spell the end of the world in a very casual and unthinking way, and they tend to do just that on a regular basis. The trick of The Eternals is that each time a Celestial is born, the world in which it grew after being seeded is destroyed so that the Celestial can give rise to many other planets and universes in an unending cycle of death and rebirth.
The Eternals are the servants of the Celestials, created and programmed to fight the Deviants, which are originally said to be creatures that came from the shadows to stand in as the new apex predators on one world after the next. The only problem was, the Deviants were supposed to help keep the balance, not create a new pecking order. Thus, the Eternals were created to beat them back and kill them off. But as anyone with a working knowledge of ecology should know, eliminating one species tends to negate the use of the means that were brought in to eradicate them, and tips the scales of nature in another direction. Humanity has been doing this for a long time, and it doesn’t always work out the way that people want. But after eliminating the last of the Deviants, as they believed, the Eternals disbanded, finding that their purpose was no longer capable of binding them.
But as it’s found out in the movie at some point, Ajak, played by Salma Hayek, who is the leader of the group and in direct contact with their Celestial lord, Arishem, knows more than she’s letting the others realize since Arishem seeded the earth with a Celestial known as Tiamut, who will eventually grow and burst from the earth, thereby destroying it. After realizing that the Deviants have somehow returned, the Eternals begin to gather their members once again as Sersi is made the new leader after Ajak dies, while Ajak’s second in command, Ikaris, turns out to be a rather shady character. It’s also discovered that Thena, played by Angelina Jolie, has been remembering her past lives and the destruction of many planets, as the Eternals are given new lives each and every time the world they’re on is destroyed so that they can continue to serve Arishem in securing new worlds and making sure the population can grow. This in turn fuels the Celestial seed, which then continues the cycle. This time, however, the Eternals are determined to stop the Emergence, aka the birth of Tiamut, but have to find a way to do so.
They also have to find a way to work around Ikaris, who is revealed to have allowed the Deviants to kill Ajak and is against stopping the Emergence since he is an individual that follows orders first and doesn’t falter. Sprite, the ageless, child-like member of the group, allies with Ikaris, while Kingo, the self-made movie star, does not side with anyone in the conflict even though he agrees with Ikaris, as he won’t raise a hand against any of his fellow Eternals. This leaves Sersi, Phastos, Makkari, and Thena to fight off Ikaris and Sprite and keep Tiamut from emerging, thereby destroying the world. By the end, the earth is saved, but at the cost of a Celestial as Tiamut is killed, which causes Arishem to retrieve the remaining Eternals so that it can determine whether their actions were justified or if earth will be destroyed anyway as a consequence of their actions.
This movie could have easily been cut into two parts and been just as good if not better since a lot of the exposition appeared to slow things down to a crawl at times. But overall it wasn’t that bad since the effects were interesting and the storylines, which weren’t really delved into as much as possible, could be great spinoffs if someone decided to do so. But in the long run, The Eternals kind of did earn their Rotten Tomatoes score, but only because this movie definitely needed a little more buildup in order to really come off as a new shift in the MCU.