In a note to her 1839 edition of Percy Shelley's Prometheus Unbound, Mary Shelley recalled that during its composition, Percy, who had been feeling persecuted by scandal, ‘sheltered himself from such disgusting and painful thoughts in the calm retreats of poetry’. Unable to defeat his ‘painful thoughts’, Shelley conjectured, her husband sought to escape them through writing. Her inclusion of this anecdote to gloss a play whose protagonist overcomes an eternity of ‘pain, pain ever, forever’ suggests her awareness of a discrepancy between the drama's plot and its effect on its author—and, in turn, a difference between two therapeutic models for literature. Prometheus Unbound is a drama of radical cure. Prometheus's embrace of love and justice heals not only himself but also his world. But as Shelley recognized, this tale about panacea offered its playwright only a ‘shelter’ of temporary relief. The story of a cure was, in practice, palliative.

The poetic shelter was a place Mary Shelley knew well. A month after Percy Shelley's death by drowning in the Tyrrhenian Sea, she adapted Prometheus's lament to mourn his loss as an irrecoverable tragedy. ‘I repeat only—“Pain, pain, ever & forever pain!”’ she wrote in a letter. A year later, she would begin composing The Last Man, a novel that documents Europe's collapse beneath its own Promethean agony, a plague that kills all but a handful of people. Yet in the same way that Shelley's biographical reading of Prometheus Unbound unsettles the play's triumphant message of healing, The Last Man resists the despair that might understandably follow its grim events. The novel's frame narrator, often read as a reflection of Shelley herself, recalls how the story's composition ‘softened my real sorrows and endless regrets … tak[ing] the mortal sting from pain’. It is striking how the narrator finds momentary relief for apparently incurable ills—their regrets are ‘endless’, their pain ‘mortal’—in a tale of terminal disease. In her journals, Shelley had commented on the novel, ‘The last man! Yes I may well describe that solitary being's feelings, feeling myself as the last relic of a beloved race’.