That's right, two opposite themes – Mortality and Immortality – occupy this poem. We find out that the memory of the speaker's death day is being told centuries into the afterlife. So, in this poem, Dickinson explores the idea of perpetual life. In this poem there is life after death, which offers an explanation as to why the speaker's so calm about everything. Death's not the end, just one step closer to eternity.
Questions About Immortality
What kind of afterlife do you imagine the speaker is telling the story from?
What makes the speaker so certain she will continue on after death? (Immortality is mentioned right away, in the first stanza.)
Do you think the speaker misses her life on Earth, or do you think she's happier where she is?
Do you agree that horses' heads signal "Eternity"? Are there any other animals you think might be capable of signaling the afterlife? Why?
Chew on This
Even though Dickinson doesn't specifically name it, the speaker is in Heaven.
The horses mentioned in the poem were actually angels, carrying the speaker to the afterlife.