Following a series of episodes that involved monster hunting, the upcoming episode of ‘Supernatural’ season 11 will turn the spotlight on one of the most crucial issues at hand, which is to seek ways to triumph over the Darkness aka Amara.

Sam (Jared Padalecki) and Dean (Jensen Ackles) are set to travel back in time as they go on a mission to find a powerful weapon, as Castiel (Misha Collins), also known as Lucifer, makes his comeback.

After Amara’s disappearance, it was recognized that the solution for her defeat can only be found in her past. As pointed out in the synopsis for episode 14 titled ‘The Vessel,’ Dean will be able to convince Castiel, who is still in Lucifer form, to let him travel back to the past to the last sighting of the Hand of God, in his attempt to seek a weapon that is strong enough to overpower Darkness.

As part of his treacherous plan, Lucifer sends Dean off to the Second World War era to get a hold of the weapon. The devil takes this chance in obtaining the weapon himself and takes on the form of Castiel, taking Dean back to 1944 and onto the unlucky submarine mission that sank the Hand of God.

Meanwhile, at present times, Lucifer will carry on with his pretentious acts with Sam and will start to secretly plan his next move in the upcoming episode.

Showrunner Jeremy Carver expressed his excitement about the new installment after offering a preview of the special time travel episode.

"We will be going back in time for an episode and we will be essentially spending an episode on a World War II-era submarine with American soldiers of the time,” he said in an interview with Entertainment Weekly. “"It's basically our version of Das Boot. The whole production team has just done an absolutely astounding job, so that's a really cool episode.”

Meanwhile, the previous episode showed the Winchester brothers investigating an ancient curse, which sought to take people’s hearts out in time for Valentine’s Day. Dean and Sam investigated an old case that had once been explored by Bobby and Rufus; the old case was first opened in ‘Supernatural’ season five.

According to Carver, there were “a lot of great throwbacks to things that happened" during such instalment, teasing a "wonderful relationship between Bobby and Rufus.”

Meanwhile, Padalecki also recently made the headlines for signing onto the ‘Gilmore Girls’ revival for Netflix. The 33-year-old actor’s return to the highly anticipated reunion miniseries had been a big question for many. The revival is expected to be comprised of four 90-minute episodes.

The ‘Supernatural’ star will make his appearance along with former co-stars Alexis Bledel, Lauren Graham, Kelly Bishop and Scott Patterson, to name a few. An official premiere date for the revival is yet to be announced.

As for the upcoming 'Supernatural' episode 14, 'The Vessel,' its official promo can be viewed below.