The prehistoric world faces its greatest meltdown yet in this fiery new adventure. As the ice age gives way to an unprecedented global thaw, the beloved herd led by the ever-worrying mammoth Ray Romano and his fiercely loyal saber-toothed friend Denis Leary finds their familiar glacial landscape vanishing before their eyes. With rivers boiling and their home rapidly flooding, the group must embark on a perilous journey to find a rumored safe haven—a mythical high ground said to be untouched by the rising heat. Their quest is complicated by treacherous new terrains, volatile geothermal phenomena, and the desperate scramble of every creature trying to survive. This thrilling and heartwarming chapter blends high-stakes adventure with the series' signature humor, as the herd discovers that their greatest challenge isn't just the boiling point of their world, but the strength of their own family bonds in the face of catastrophic change.