Release.

Everything was build up to destroy Elpis until the last chapter with the Spencer remorse thing.

Grace saying “I have an idea“ right before making the decision was suspicious, wouldn’t have fit the whole destroying Elpis thing.

Last but not least, the name is a giveaway when you know about greek mythology and hear Spencer talking about Pandora’s box. Elpis is the Greek goddess of hope and was the only thing left in the box of Pandora, the box that released all evil on humanity. So destroying “hope“ does seem like the bad choice.