Caught between human greed and an unstoppable alien power, Kate Stewart leads her closest allies on one final, desperate mission. This could be the very last chance for the human race. But the UNIT team has been declared rogue, and ruthless military forces are in pursuit as they race across the globe. Kate calls Lieutenant Sam Bishop to their aid, while Josh and Osgood head out across the frozen Antarctic plains to try and prevent a disaster no-one else knows is coming.