'Supernatural' season 12 spoilers: One Winchester in life or death situation?

A foreboding new preview for "Supernatural" season 12 has been released, teasing a tragic fate for one of the Winchesters and the people who are witnesses to the family's legacy are doing their best to stop it.

The teaser shows Dean (Jared Padalecki), Sam (Jensen Ackles) and Mary (Samantha Smith) in full attack mode. At some point in the "Supernatural" season 12 clip, the Winchester matriarch uttered the words, "I love you" before a gunshot rang.

"This sad, doomed little world, it needs you. It needs every last Winchester, and I will not let you die. I won't let any of you die," Castiel (Misha Collins) can be heard saying.

Crowley (Mark Sheppard) also confessed in the "Supernatural" season 12 clip how much the world needs the Winchesters and how important it is for them to survive.

The clip teases that "Supernatural" season 12 will be teeming with dangers and threats that could put Dean, Sam and Mary in grave danger. Whoever it is, it will definitely push the others to team up to do something about it.

The show will return to the small screen this week with "First Blood," which will see Dean and Sam taken into custody by the government after the attempted assassination of the president.

Mary and Castiel team up to get them back, but this will be no ordinary mission. Because of this, they will find themselves working with an unlikely ally.

While it is expected for them to be able to save Sam and Dean in "Supernatural" season 12, episode 9, it will be interesting to see just how they do it.

Meanwhile, details about upcoming episodes of "Supernatural" season 12 also spell trouble for both Castiel and Dean.

One involves one Lily Sunder (guest star Alicia Witt) using black magic to serve up revenge on angels like Castiel. Another involves Dean's memory being erased.

"Supernatural" season 12 returns with episode 9, "First Blood," on Thursday, Jan. 26, at 8 p.m. ET on The CW.