During the story, strange things keep happening like alien kidnappings or other events. The nature of the 'others' isn't revealed until towards the end.
I remember a question by a protagonist to the others near the end of the book goes like, "Is there intelligent life out there?" To which the response was, "Not any more, we won."
The 'Time/Spaceship' was called a 'pa' after the traditional Maori settlement, and it is implied (or maybe even stated) that a calamity was going to affect the earth and that the protagonists should head to New Zealand, thus perpetuating the timeline.