Surviving in a volcanic world is tough enough, but caveman Grug (Nicolas Cage) gets a rude awakening when an earthquake forces him to leave behind the only world he knows. With his family in tow, he ventures out into the volatile world in search of a new home. The situation becomes even more complicated when Grug's family - but in particular his eldest daughter - become smitten with a nomad (Ryan Reynolds) they encounter on their dangerous journey. This quirky, imaginative stranger's search for 'tomorrow' is at odds with Grug's reliance on the traditions of yesterday. Written by DreamWorks Animation