Childhood’s End by Arthur C. Clarke

Countless times this day had been described in fiction, but no one had really believed that it would ever come.

This novel starts with the scene that the great ships visits the Earth. And the visitors are…

Yes, we are the midwives. But we ourselves are barren.

They look like the symbol of fear and evil:

Image of the ‘Overload’ from Syfy’s drama
For that memory was not of the past, but of the future - of those closing years when your race knew that everything was finished. [...] Call it not a memory, but a premonition.

It was published in 1953 but it still rocks!