随着时间在他们家窗户关闭之前所剩无几，天坑的幸存者进行了最后的逃生尝试。 然而，当他们收到加文的严厉警告，他们的计划将以灾难告终并迫使夏娃做出不可能的选择时，该计划受到了质疑。

Desperate to reunite with her son, Eve follows a lead that brings her face-to-face with a ruthless prehistoric group. Gavin, Izzy and Ella question whether they’re fit to survive in 10,000 BC. Josh and Riley wake up in an unfamiliar time.