"We dream -- it is good we are dreaming --"

We dream -- it is good we are dreaming --
It would hurt us -- were we awake --
But since it is playing -- kill us,
And we are playing -- shriek --

What harm? Men die -- externally --
It is a truth -- of Blood --
But we -- are dying in Drama --
And Drama -- is never dead --

Cautious -- We jar each other --
And either -- open the eyes --
Lest the Phantasm -- prove the mistake --
And the livid Surprise

Cool us to Shafts of Granite --
With just an age -- and name --
And perhaps a phrase in Egyptian --
It's prudenter -- to dream --

F (584), 1863

This poem sees Dickinson continuing to indulge in the exploits of the vaguely macabre, as it appears to offer a somewhat surreal endorsement of nightmares and theatrical death as a means of feeling a connection to the concept of one's mortality without dying in actuality. The notion of "playing" along with these imaginary deaths is juxtaposed by the recognition that, while death represents an undeniable fact of life, the stark imagery of suddenly being reduced to mere "Shafts of Granite" places an alienating and cold finality that the comparative sublime ideal of "dying in Drama" does not. 

It is particularly worth noting that the date of the poem's writing would have positioned it right during the middle of the Civil War. In a situation where "Men die -- externally" in massive quantities every day and the "truth -- of Blood" would have been virtually ever-present and unavoidable in the news, one can understand why the concept of imagined death in a nightmare or fictional death in a play or other form of drama where the knowledge that it wasn't really happening would have served some form of comfort, maybe even providing a kind of therapeutic tool to help come to terms with that real life carnage. 

A Nightmare on Elm Street (1984) presented a scenario in which it was not
"prudenter-- to dream --"

In a modern context, it's hard not to associate this poem and its message with the immense popularity and longevity of the horror film genre. As Dickinson states, "Drama -- is never dead --" and the success of decades of films spotlighting all kinds of varieties of gruesome deaths and nightmares captured on celluloid has certainly proved that point in spades. There is an undeniable catharsis that comes from being able to view the darker, more morbid aspects of existence through a "prudenter" imagined lens. It allows us to fathom our own mortality and, in a broad sense, the human condition as a whole, in ways that give us a taste of that fear without actually putting us in danger of the "Phantasm -- prov[ing] the mistake." It's interesting to examine how the poem's interplay between dreams and death has been mirrored by the development of the genre as well, with high profile series like A Nightmare on Elm Street and heavy reliance on dream logic emphasized in the works of Italian auteurs like Dario Argento (Suspiria, Deep Red) and Lucio Fulci (The Beyond, City of the Living Dead). The combined effect of these directors' vibrant use of color, fluid, POV-style camerawork, and elaborate, often nonsensical plotlines function to emulate the powerful feelings that can come from a harrowing nightmare, touching upon that certain sense of the sublime that Dickinson hints at in the poem.