The poem is spoken by Lady Lazarus, a speaker who shares a lot of similarities with the poet herself. Lady Lazarus begins by telling us that she has done "it" again. What is this "it"? We don't know at first. She compares herself to a Holocaust victim, and tell us that's she's only thirty years old, and that she has nine lives, like a cat. We soon figure out that "it" is dying; but, like the cat, she keeps returning to life.
She tells us about the first two times that she almost died, and tells us that dying "is an art." She says that dying is a theatrical event, and imagines that people come and see her do it. In fact, it starts to seem as if she's performing a third death in front of a crowd at a circus or carnival. She compares herself again to Holocaust victims, and imagines that she's been burned to death in a concentration camp crematorium. At the end of the poem, she resurrects (or returns to life from death) once again, and she "eat[s] men like air."