In Greek mythology, hope was left inside Pandora’s container after the evils escaped. Hesiod’s Works and Days says that Pandora replaced the lid after the harmful forces had flown out, leaving only Elpis, the Greek personification of hope, within the vessel.
The ending has generated centuries of debate. Some readers interpret hope as a comfort preserved for humanity, while others note that the story does not explicitly say whether hope remained outside because it was beneficial or inside because it was another withheld force. The Greek word elpis can also mean expectation, not only optimistic hope.
The familiar phrase “Pandora’s box” is itself a later mistranslation. Hesiod described a large storage jar, or pithos, rather than a small box. Renaissance retellings helped establish the box image in European languages.
Regardless of interpretation, hope is the standard answer in modern retellings and reference works. It is the final element named in the myth after the world’s afflictions are released.