*CUT TO THE CHASE*
This spoiler was submitted by Jeremy
Europe, 20,000 Years Ago - A tribe gathers near a herd of buffalo. The leader, Tau (Johannes Haukur Johannesson), gives the signal, and the men charge toward the buffalo. As the beasts stampede toward them, the men hurl spears to divert their path. The buffalo run toward the edge of the cliff, and most of them fall over to their deaths. Tau's son Keda (Kodi Smit-McPhee) attempts to kill a buffalo, but he instead runs away from it, and the buffalo charges toward Keda and knocks him into the air. The buffalo runs back toward him and picks Keda up with its horn. It runs toward the cliffside, and Tau hurls his spear to stop the buffalo, but as it makes it to the edge, Keda flips off the buffalo's horn.
One week earlier, Keda and other boys in his tribe were being prepped for an initiation as hunters. Some of the boys fail to make sharp spearheads, but Keda is among the few that succeeds. Afterwards, the boys are forced into a brawl before Tau tells them to stop. He then goes to Keda to tell him what will be expected of him as he steps up to become a leader like his father. Later at night, Tau talks to his wife Rho (Natassia Matlhe) about Keda, and she feels that he could not be like Tau because Keda leads with his heart, not his spear.
The men leave the women and their homes to go on a hunting expedition. Keda is at one point tasked with trying to start a fire, but he cannot do it. On the way, they run into another tribe led by Xi (Jens Hulten), an old friend of Tau. The two tribes take the younger men to hunt, and they first go after a boar. Tau orders Keda to deliver the finishing kill to the boar, but Keda cannot bring himself to do so. Tau slits the creature's throat before chastising his son for failing to do so.
The men continue moving forward. Tau teaches Keda that, if he needs to find his way home, he must look up at the stars, as well as the paint on rock formations left by the ancestors to guide them home. They also encounter a pack of wolves, and Tau points out to Keda which one is the alpha. The tribes then set up camp for the evening around a fire. They are stalked by a sabre-toothed tiger that kills a man from Xi's tribe. In the morning, the men leave a rock pile as a tribute for their fallen comrade.
The tribes then gather for the buffalo hunt. After Keda is flung over the cliff, he is left hanging on for his life as Tau tries to reach him. The rock he's holding breaks off, and he falls further until he hits an edge halfway down. Tau attempts to climb down to get him, but Xi and the other men stop him, saying it's hopeless. Tau is left to accept that Keda is gone, and they leave a rock tribute for him as well. Tau and his men make their way home, and they part ways with Xi's tribe.
Keda wakes up and finds himself still high up over the buffalo carcasses. His ankle is also broken and swollen. He starts trying to climb down, but he knows he is too high. Keda hangs on until a storm comes and starts to flood the chasm below. After a brief hesitation, Keda lets go and falls into the water.
Keda is washed up in an unknown area. He relocates his ankle and makes himself a cast to allow him to walk. As he tries to make his way back home, he is found by the pack of wolves. They chase him, and he climbs up a tree for safety. The alpha gets close to Keda, and he slashes at her with his spearhead. Keda waits for the other wolves to leave, and he notices the alpha lying helplessly, still wounded. Despite being weary of the wolf's nature, Keda takes pity upon her and carries her to a cave where he treats her wound.
Keda and the wolf (whom he later names Alpha) stay in the cave for shelter. He tries to give her some water and appear friendly, but she growls at him. Later, Keda makes his first kill by hunting a rabbit and eating it and sharing some of the meat with Alpha. When Keda is ready to head back home, he tries to send Alpha away on her own, even having to get aggressive, but she instead follows him back.
On the journey back, Keda tries to hunt a boar with Alpha's help. She mauls it, and they feast on its remains. They also have to avoid a pack of hyenas that stalk them. Keda sets up a campfire, and a coyote approaches them menacingly. Alpha walks up to the coyote and nestles her face into his, leaving it to run off without a fight.
A heavy snowstorm starts to hit the land. Keda and Alpha are walking across what he doesn't realize is a frozen lake. He sees another pack of wolves feasting on a carcass, and he worries it's Alpha. Keda runs toward them and ends up falling through the ice. Alpha tries to reach Keda, but he breaks through the ice with his knife. He sets up another fire and removes his cold, wet clothes to share warmth with Alpha.
As the two continue on their journey, Keda starts to suffer from hypothermia. He and Alpha come across the hut of another man whom Keda finds frozen to death. He goes through the man's home to find food, but there is none. Keda takes the man's bow and arrow, thanking him for providing for him. The two continue moving onward until they reach a cave where the tiger finds them. Keda preps the bow and arrow before Alpha lunges toward the tiger. The two fight until Keda strikes the tiger with the arrow. However, Alpha has been pretty badly wounded. Keda tends to her wounds as she lays by him.
The weather becomes worse, and Alpha is barely able to keep walking. Keda lays by her as he grows weaker as well. He passes out in the snow and then starts to remember the conversation he overheard his parents having about him. After Rho said that Keda leads with his heart and not his spear, Tau responded that Keda is stronger than even he realizes. This gives Keda the encouragement and push to stand and carry Alpha.
Keda spots the ancestral paint on the rocks, and he realizes he is close to home. Sure enough, he spots his tribe. He walks in while carrying Alpha, and Tau runs to his son and brings him and Alpha inside for shelter and warmth. As Keda recovers, the Shaman (Leonor Varela) tends to Alpha. To Keda's surprise, Alpha has given birth to a group of wolf pups. The Shaman commends Keda and Alpha for bringing new life to the tribe.
Keda and Alpha fully recover, and they are seen watching the sunset with the pups. When they are fully matured, the wolves join Keda and the other tribesmen for a new hunt.