Summary
After describing the way the fish in the cave seem to eat her body, the speaker describes her candle sputtering. It doesn't go out, and the flame returns to light her way in the dark mine. Next, the speaker abruptly addresses her child, asking him about his origins and highlighting his smallness and newness by calling him "embryo." Even while asleep, he lies in a fetal position. His blood is new and clean, and his mother expresses a desire to protect him from pain. She tells him that she will hang roses and rugs in the cave they share. The stars and atoms might fall apart, and the world might end, but, the speaker tells her baby, he is a solid thing in a vast empty space—so much so that the emptiness both leans on him for support and envies him. The speaker closes the poem by calling her child "the baby in the barn."
Analysis
In the first half of the poem, it's not particularly obvious that the speaker is addressing her child, or that she is a mother at all. At around the halfway point, Plath reveals the speaker's identity and situation with a series of clever transitions. First, still immersed in the mine allegory, the speaker imagines strange fish feasting on her, drinking from her toes. She then switches images and talks about the candle she carries through the mine. However, when describing the way the candle threatens to blink out, she uses the word "gulps," implicitly connecting the candle to the fish. Then, while still describing the candle, the speaker apostrophically wonders, "O love, how did you get there?" It seems she is addressing the candle, but as she continues, it becomes clear that she is also addressing a child. This suggests that the fish, the candle, and the child are related. This tells us a lot about the mother's outlook and condition. For one thing, the fish drinks and the candle gulps, so this may imply that she is breastfeeding her child. Meanwhile, the fish is described as predatory and threatening, a "piranha," while the candle is a source of comfort and guidance. In other words, we might assume, the child can feel like both a bizarre and frightening creature, and like an adored companion.
The poem is also packed with religious allusions, although they actually begin further up, in stanza five. They start quietly, with the speaker calling the fish in the cave "holy Joes." She then exclaims "Christ!" in reference to the fish. On its own, these seem like they may be expressions of emphasis and surprise, rather than overtly religious or Christian references. But religion crops up in the following stanza too, when the speaker compares the fish to "a Piranha/religion." The speaker describes the fish consuming her body, and calls this a "first communion." Then in stanza nine, the speaker refers to her child's "crossed position," which in context can be considered a subtle reference to Christian iconography. She also mentions his pure, clean blood—an important moment, given that the practice of communion consists of consuming wine that is said to take the form of Christ's blood. For a while, the speaker makes no clear references to Christianity. But the last line, in which she describes her child as "the baby in the barn," is very clearly a comparison between her child and Jesus, who, according to the Bible, was born in just such a place.
What are we to make of these allusions? On the one hand, the speaker is clearly comparing her son to Jesus. This occurs most overtly in the final line, but the references to his blood and his crossed position buoy the comparison. Indeed, so does the exclamation "Christ," and the reference to holy fish, since (as discussed above), we have reason to think that the fish is one metaphorical representation of the speaker's baby. These comparisons suggest that the speaker is a kind of religious devotee, and her child a messiah or savior. But, on the other hand, the poem's metaphorical linkage of breastfeeding to communion also suggests that the child is the devotee, and the mother the savior. Ultimately, the poem seems to hint that it goes both ways. Both mother and child need one another, and each one serves as a kind of savior or even a deity to the other.