This poem is an extended metaphor, in which the speaker’s life becomes a loaded gun, as defined in the first line. The gun is unused for the first stanza, until its owner recognizes it and takes it away with him. In the second stanza, the gun and the owner become closely connected, traveling together through the woods in pursuit of the deer they are hunting.
Whenever the gun is fired (“And every time I speak for him –“), its boom is echoed by the mountains—their “straight reply.” Similarly, when the gun is fired (“And do I smile”) there is an explosion of light (“such cordial light/Upon the Valley glow –“), which illuminates the valley (“It is as a Vesuvian face/Had let its pleasure through—“).
When the owner goes to sleep (“And when at Night – Our good Day done –“), he has his gun by his bedside to protect him (“I guard My Master’s Head –“), and the gun prefers this role to sleeping with the master (“’Tis better than the Edier-Duck’s/Deep Pillow – to have shared –“). The gun warns that to any enemy of his master’s, he will prove to be very dangerous (“To foe of His – I’m deadly foe –“). No one who he is fired at, that is, who sees his explosion (“On whom I lay a Yellow eye –“) or who is on the wrong end when he cocks the gun (“Or an emphatic Thumb –“), will survive (“None stir the second time –“).
The gun will live longer than his master (“Though I than He – may longer live”), but it is not true living, because he is “Without – the power to die –.” It is death which defines life, thus though he may last longer than his master, his master in the true meaning of the word will outlive him—“He longer must – than I –.”
There are two conventional understandings of the metaphor of this poem. The first is that the “Master” is God, and so, picked up by God, the speaker becomes his marksman. She is his staunch defender, and in fulfilling this role, becomes powerful—she shares his voice, acts only at his bidding, and is in some way immortal. In this reading, then, choosing to serve God is a way to further your own power and existence.
The second conventional reading is that the “Master” is not God, but a lover. The speaker only gains agency or power when she is identified by this lover, and carried away by him. In the second stanza they are fused; they are “We,” she becomes his voice and guardian. Her guarding of him, however, is fierce, fueled by a murderous and possessive fury to such an extent that, though a bed is mentioned, it is not a sexual place but one of violence, where she guards him jealously. She in fact explicitly states that she would rather guard him than share the bed with him.
In either case, whether the Master is deity or lover, the central dilemma of the poem is that of the fusion of the gun and its owner, the force and the agent, the violence and the perpetrator. This becomes very clear in the second stanza, where the speaker and her owner fuse together into a “We,” and this is emphasized further by the anaphora of the first two lines of that stanza. In addition, the gun, in going off, is communicating for the master—“every time I speak for Him –“—taking on his voice.
In the fifth stanza, too, the speaker and the owner are almost indistinguishable—the “Yellow Eye,” a very human feature, actually refers to the gun’s explosions, and the sentence grammatically reads “On whom I lay…an emphatic Thumb,” but the thumb is clearly actually that of the owner, who is cocking the gun. The poem’s final stanza makes the two entities distinct again, although it ultimately fuses them in tying their lives and deaths together, and in making this interdependence complicated enough that it is nearly impossible to extricate one from the other.
This poem, like so many of Dickinson’s, deals with the theme of death, but here, unusually, it is not death that is powerful, but the ability to die. This shows how intricately life and death are tied up, and how life cannot exist without death, for while the gun “may longer live” than the human master, it never really lives at all “Without – the power to die –.” How closely this last stanza ties everything together is made clear in the abundant repetition within it—“longer,” “the power to,” “than,” “He,” and “I.”