[[ice age 4Plot
As in the previous films, the main protagonists are the mammoth Manny, the sloth Sid, sabre-toothed cat Diego, and, in a parallel storyline, the saber-toothed squirrel Scrat. Scrat's hunt for acorns triggers the break-up of the Pangaea continent into the continents as we know them today. In the meantime, Manny and his wife Ellie deal with their 15-year-old daughter Peaches who has a crush on a mammoth named Ethan. Peaches' best friend, a molehog named Louis, also appears to have a crush on her. When Manny catches Peaches hanging with Ethan after he told her not to, Manny and Peaches argue and have a falling out. Soon after, the breakup of the continent separates Manny from his family. Manny gets stuck on a floating ice raft together with Sid, Diego, and Sid's annoying grandmother Granny. A large moving landmass drives Ellie, Peaches, Crash and Eddie, Louis, Ethan, and a herd of other animals towards a land bridge, where they hope to reunite with Manny.
Meanwhile, Scrat, lost at sea also, finds an acorn-shaped map, which leads to a mysterious acorn-filled island. Scrat decides to follow the map and find the island, but as he begins his journey, he is suddenly captured by a gang of animal pirates on an large ship-shaped iceberg, who are sailing the oceans.
Manny and his friends are captured also by the pirate gang, led by a giant ape named Gutt. Gutt and the pirate gang attempt to persuade Manny to leave family life and join the pirates, but he refuses. Gutt takes this as an insult, and attempts to make the herd walk the plank, but they (along with Scrat, who continues his journey) manage to escape, in the process destroying the pirate ship, and again float on the oceans on a small ice raft. They rescued a female pirate saber-toothed cat who had been left behind by the pirates. She reluctantly joins the group, though states that the pirates will come back for her.
The group reaches an and encounters a group of hyraxes as well as the pirates, who are building a new ice ship elsewhere on the same island. The herd plan to steal the ship and use it to get back home. The next morning, as the herd is preparing their plan, Shira escapes and rejoins the pirates, but gets reprimanded by Gutt instead of being welcomed back, after Gutt realized that she had been with the herd, and had not attacked them. The herd, along with the hyraxes, overtake the new ice ship and, with some help from Shira, who changed her mind after being reprimanded by Gutt, sail away. Gutt, in anger, quickly turns a new iceberg into a ship, propelled by narwhals, and chases Manny's gang, determined to get revenge.
Meanwhile, Peaches has been still hanging with Ethan and a group of teenage mammoths, but after realizing that they don't care about the danger and thinking that being a best friend with a molehog is ridiculous, she leaves them and returns to Louis. When Ellie, Peaches, Louis, Crash and Eddie reach the land bridge, they find it to be destroyed. Meanwhile, Manny, Sid, Granny and Diego encounter depicted as sharp-toothed creatures who take the shape of loved ones and attempt to lure the sailors. Fortunately, Manny realizes this and manages to steer the ship away from the sirens. Later, Scrat meets a siren, which uses the shape of his former girlfriend from the third film, Scratte, to attempt to lure him. When this fails, the siren takes the shape of an acorn, causing Scrat to run up and hug it. The siren changes back and attacks Scrat, but he gets away.
The next morning, Manny, Sid, Diego and Granny finally reach home, but, much to their horror, find out that Gutt and his pirate gang had beaten them to it and captured Ellie and Peaches. Diego also notices that Shira appears injured, possibly from Gutt due to her betrayal and change of allegiance. Manny attempts to turn himself in to Gutt in exchange for releasing his family, but Gutt doesn't keep his side of the bargain and prepares to kill the family. However, Louis, Ethan and the teenage mammoths come to rescue, starting a battle, during which Shira joins them, and Granny's presumed imaginary pet Precious, a large sperm whale (a Livyatan melvillei), appears, defeating the pirates. Peaches rescues Manny, but as they are about to escape, Gutt attacks him again. Gutt and Manny engage in a final fight, but Manny manages to defeat him. Manny arrives in time to pick up Ellie and Peaches, who are caught between the moving landmass and the ocean at the location where the land bridge once existed. Meanwhile, Gutt is killed when he ends up being devoured by a siren, taking on the shape of a female of his species.
After sailing over the ocean, the herd and all the animals find a new home. Manny and Peaches embraced and reconciled, Manny finally admits that Sid is not the screw-up after all, but a hero, while Louis is finally allowed to still be with Peaches whenever she hangs out with Ethan's gang. Shira joins the herd and she and Diego share a loving look together.
The film ends with Scrat finally reaching the island on the map, Scratlantis (a Scrat version of Atlantis), a floating city filled with other sabre-toothed squirrels and nuts. But because of his nut obsession, Scrat grabs many nuts in a frenzy and sooner or later, he tries to grab a giant one blocking a hole. He grabs it, despite the sabre-toothed squirrel leader's warnings, causing the city to sink to the bottom of the ocean, leaving Scrat in the middle of a newly-created land: the desert. Scrat's eyes burn, and he screams in pain and frustration.
The whole herd in the end credits dance to we are family and during the song Diego and Shira are brifley seen nuzzling each other comfirming they are now a couple. Ice Age: Continental Drift