Teaser scene

The ground began to shake and rumble. They all stumbled around, trying to keep balanced. Nicky grabbed onto Gabriel with a death grip. She looked up and saw the terror in Gabriel's gold eyes. He was terrified of the Leviathan and he was going back. He had been fighting it since the beginning of time. He had been tortured by it since the beginning of time. He was only doing this because the others had asked him. Nicky clutched his arm trying to give him some comfort. The ground shook once more and she fell to my knees. Fear and panic spilled through her as the ground opened. This wasn't the jagged crooked line of an earthquake. It was straight and perfect, like someone had cut through the earth with a pair of scissors. A hand touched Nicky's hair. She looked up and Gabriel smiled at her.

"I'll protect you," he whispered. She looked across the divide to Sam, Selirra, Dean, Castiel and Lucifer. Sam and Selirra were yelling something but she couldn't hear them. She looked back up at Gabriel and saw fear flash across his face. Too late she realized that the ground was crumbling beneath him. She looked up once more as Gabriel stepped away.

Gabriel. Her mouth formed the word but she couldn't speak as she stretched out her hand. He reached for me but then the ground under him gave way and he was falling. He fell into the darkness and the earth closed above him.