Childhood's End is Arthur Clarke's version of Aliens Amongst Us...and quite an imaginative one!
Sometimes fopr me, Sci-fi from the 'golden-age' can be a little dated, which leads to a sort of boring quality. This did show it's age, especially in the males regard for the females, so I was a little concerned that the ending was going to be kind of twilight Zone like, but once the story took over it became clear CLarke was going to a different place, and I just sat and enjoyed the ride....