The original series of 'V' in the 1980 saw the Visitors led by Diana trying to enslave the planets population. The Visitors wanted humans as soldiers and as a food source.
In the remade series, the Visitors were led by Anna. What did the Visitors want with Earth and its population, it was hard to see what the Visitors ultimately wanted as it was so drawn out. Did the Visitors want the same objectives as the originals or what were they?