The atmosphere that is created very early on in this poem is one of strange, eerie silence that clearly speaks of the mass destruction and disaster that has fallen the world due to the war that is referenced at the beginning of the poem. Note the way that this silence is described and characterised:
By then we had made our covenant with silence,
But in the first few days it was so still
We listened to our breathing and were afraid.
On the second day
The radios failed; we turned the knobs; no answer.
The reference to the sound of the people's breathing that made them afraid combined with the lack of radio contact serves to create an atmosphere of fear and trepidation. This is supported by other signs of the "dead bodies" piled up on the deck of the passing warship and the plane "plunging" into the sea. These events speak of massive death and destruction, but part of the unsettling feel that is created derives from the lack of a clear explanation that is given about what has happened and precisely the reasons for these strange events. The reader is left curiously wondering what is going on and what the fate of these people left stranded in a post-apocalyptic state will be.