One of the frequent charges made against Emily Dickinson is that she was obsessed with death, mortality and dying. This poem is of course one of her poems that fits into these categories, as it personifies Death as a gentleman caller, who takes the speaker on a ride in his carriage. This is a highly imaginative presentation of Death as a non-threatening individual - a proper gentleman caller, who, of course, has a chaperone in the person of Immortality. the speaker in the poem describes what she sees out of the window, and then describes how she begins to feel cold. The house to which death brings her, like a bridegroom conducing his bride to a new home, is a fresh grave. Here, however, they only pause; their ultimate destination lies further on. Moving to the present tense the speaker then reflects back on the moment she first realised she was moving toward "Eternity".
Although such poems initially appear morbid to the present day reader, we need to understand them within the context of the time. There was the constant threat of tuberculosis; what we might consider common unimportant illnesses today, such as pneumonia, then often led to death; even pregnancy and childbirth were far more dangerous than they are now. For Dickinson, as for us all, Death is the one completely unknowable experience, and thus she devoted much of her poetry and time to imagining his many faces. Thus the key thing for you to think about is how Death is presented in this poem and in others.