Crowley knows that if there's a right time for Sam and Dean to stop Amara, it's now. That's why in "Supernatural" season 11, episode 17, titled "Hell's Angel," he will offer his help to the Winchester brothers.

After their long, fruitless search, Sam and Dean will realize that Crowley has the answer to their Darkness problem. The solution, as Crowley reveals in the "Supernatural" season 11 promo, comes in the form of the Horn of Joshua.

Of course, knowing what the Horn of Joshua is all about is one thing, and acquiring the powerful instrument is another story. "Did I say it will be easy?" Crowley tells the duo. Sam is growing more and more worried about Amara's plan to "delete the universe" coming to fruition.

So far in "Supernatural" season 11, Amara has committed tons or murders and troubles in the name of settling scores with God and until he listens to her plea, Amara will not stop destroying all of his brother's precious creations.

While Sam, Dean and Crowley wrack their brain in stopping Amara in bringing hell on Earth in "Supernatural" season 11, episode 17, Lucifer will be busy doing the same thing – to bring hell in heaven.

Lucifer, still wearing Castiel's face, will be paying a visit there and will be trolling the angels. "If it makes you comfy, you could call me God," the man tells the angels gathered around him in the "Supernatural" season 11 promo.

The angels were understandably horror-struck upon hearing this. Lucifer, on the other hand, flashes a grin as he says the shameful words, as if he is satisfied with the reaction he generated. Needless to say, Castiel, who is known as one of God's most loyal angels, will be in an awful lot of trouble.

"Supernatural" season 11, episode 16, "Hell's Angel," airs April 6 at 9 p.m. ET on CW.