|“||Peter: "Lydia, don't hold back on me. I've never held back on you."
Lydia: "I saw you... turned to stone. I was in a storage container. It was steel, there was a blue wall... I saw everyone, even Derek and Ethan. All of you turned to stone."
Peter: "Do you see anything remotely optimistic?"
Lydia: "It's optimistic if you prevent it."
Petrification is the power to petrify a living being into stone. It is a power possessed by the Anuk-ite, an ancient and powerful shapeshifter composed of two beings who was previously imprisoned by the Ghost Riders of the Wild Hunt. This power can only be accessed and used when the Anuk-ite's two halves have merged; once this has happened, the Anuk-ite can petrify beings into stone just by making eye contact with them.
Humans who make eye contact with the Anuk-ite are turned completely into stone and are killed forever, but shapeshifters and other supernatural creatures with accelerated healing powers can be saved and returned to their normal forms if the Anuk-ite can be defeated in time. This is what occurred after Peter Hale, Ethan Steiner, Jackson Whittemore, Malia Tate, and Derek Hale were petrified after making eye contact with the Anuk-ite; when the Anuk-ite was defeated when Stiles Stilinski surrounded it in Mountain Ash and caused its own powers to be rebounded on itself, all of the aforementioned McCall Pack members and allies were able to break free of the stone surrounding them.