Loneliness is usually described as an absence, but here it takes on a body. The speaker's only companion is a shadow that "lies there beside me", close enough to suggest a bed, a partner, someone who shares the room. The label above the poem, "(Loneliness)", tells us the theme outright. The more interesting question is how the poem makes emptiness feel like company, and what it costs the speaker to believe in it.
The first stanza sets the tone with its thin, bleached vocabulary. The shadow is "wispy and bare", and the stanza ends on "Hollow and hollow". The line is odd, because we expect a second, different adjective, and instead the word simply repeats. The effect is an echo with nothing inside it. The shadow is hollow, and so, by implication, is the speaker, so that the two hollows face each other like mirrors. The words above the poem, "Mobius World", suggest a loop with only one side, and whether or not that was intended, the poem keeps circling in this way. The shadow comforts the speaker, the comfort depends on the dark, and the dark keeps the speaker alone.
The second stanza turns defensive. "You ask why I am in the dark?" invents a listener, perhaps a worried friend, perhaps the reader, and the speaker answers with a calm that sounds rehearsed. The word "dark" appears three times in two lines, as if repetition could make the choice sound reasonable. Then comes the broken-off line "Not the Devil, mind but...". The dots are the poem's most revealing moment. The speaker rushes to deny something sinister, and then the sentence stops. The next stanza supplies the answer, though not as a name: "Truth, cold bitter truth". The shadow is not evil, the speaker insists, only honest, and honesty here is cold and bitter, not warm.
A pattern of "only" builds through the poem. The shadow is first "my only companion", then "my only man", "my only ally" and finally "my only friend". The relationship grows more intimate and more serious with each step, from someone who is merely present, to a lover, to a comrade, to a friend. That last word carries the farewell. Every "only" also reminds us of how little the speaker has. The repeated structure of "That he is my only man / That he is my only ally" sounds like someone talking themselves into a belief.
The imagery turns darker in the third stanza. "Blood is hidden in black" is deliberately open. Judging by the imagery, it suggests pain or violence that the darkness conceals and the light would expose. This explains the reversal in the last stanza, where the speaker says "I curse the light / For it's a murderer." Light is normally the symbol of hope and safety. Here it is the killer, because it destroys the speaker's one companion, and because it would reveal what the black hides. A shadow cannot survive in bright light, so the logic is easy to follow.
There is also an irony the speaker never quite admits. A shadow can only exist where there is light to cast it. The friend the speaker loves is made by the thing the speaker curses. The poem's claim that "He is always there in the dark" is also undercut by its own ending, "Goodbye friend". A companion who can be sent away, or who simply vanishes, was never as constant as the speaker wanted to believe. The farewell is left unexplained, which makes it ambiguous. It could be the ordinary parting of a shadow at dawn, or something more final.
In form the poem is free verse, in four quatrains with short, plain lines and no regular rhyme. The nearest thing to a rhyme comes early, in "bare" and "there", and it fades quickly. The lack of a steady pattern suits the subject, since nothing in this world holds together neatly. The language is simple and the syntax sometimes unfinished, and the roughness makes the voice feel unguarded rather than polished.
The poem matters because of the way it reverses the usual symbols. Loneliness is made concrete and given a name, and the dark becomes a refuge. The speaker's loyalty to a mere shadow is moving and also troubling, because the poem leaves us wondering what it means to be this alone.