Jim Beaver returns to Supernatural this week as Apocalyptic World Bobby and you're about to see a whole new side of him when the militant leader becomes an ally for Mary (Samantha Smith) and Jack (Alexander Calvert). Despite offering them a safe place to stay when they escape from Michael (Christian Keyes), Bobby nearly breaks the newfound alliance after learning who Jack really is.

In this exclusive preview of the thrilling episode, Mary reveals that Jack is a nephilim — an angel-human hybrid — and Bobby isn't too thrilled about welcoming the powerful stranger into his encampment. "What I don't get is why the hell you would bring one into my camp. You know what angels have done to us," he tells Mary before declaring that he wants Jack gone by morning.

Supernatural: Prepare to See a Different Side of Apocalyptic World Bobby

However, Mary isn't willing to part with the young man who came to her rescue. "If he goes, I go with him," she responds. Bobby honors her choice but not before dishing out a friendly warning.

"When Lucifer and the demon army rose out of hell, we thought the angels were on our side. But one by one, they turned on us. He will, too. It's just a matter of time," he says. But is he right about Jack?

Find out when Supernatural airs Thursday at 8/7c on The CW.

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Samantha Smith, Jim Beaver, Alexander Calvert; SupernaturalSamantha Smith, Jim Beaver, Alexander Calvert; Supernatural