The speaker describes a dream in which they race through a crowded railway station, desperate to catch a train. They weave past sleeping beggars, patient travelers, vendors and policemen, rushing from platform to platform. The detail is vivid and ordinary: dust, sweat, tired faces, sacks of mail. Nothing about the setting feels fantastic, which makes the urgency feel real.
Then the body gives out. The speaker feels a crushing pain in the chest, an emptiness in the mind, and a weariness that creeps upward "like invading armies of ants." Leaning against a cold iron pillar, they can only watch as the train pulls out in the morning light, "Without me."
The mood moves from frantic panic to exhausted defeat. The short final lines feel like a door closing. The poem suggests anxiety about missing something important, perhaps a chance or a journey, and the helplessness of a body that cannot keep up with the will.