THE BLACK CLOUDS SURROUND BLUE HEAVEN

Anne says,

"I see the eight of us with our 'Secret Annexe' as if we were a little piece of blue heaven, surrounded by heavy black rain clouds."

Anne understands that as hard as it is living in the Annexe, it is still Heaven for them compared with the dark Nazi evil that surrounds them outside. The Annexe becomes a metaphor for an oasis amidst destruction.