This week's episode focuses entirely on the overarching plot of the season, with Sam and Dean arguing with Crowley to give them the Horn of Joshua to try to defeat Amara; Amara teaming with a revived Rowena so that she can heal from the attack on her by the angels, and Lucifer cowing the angels of Heaven into helping him try to defeat Amara.
The episode is very complicated, yet not very interesting. It cuts back and forth between a series of discussions being had by all the main players. Crowley won't hand over the Horn of Joshua to Sam and Dean without their help to seal Lucifer back in his cage. Sam wants to use Lucifer (the only one who can wield the Horn) to kill Amara. Dean just wants Lucifer ejected from Castiel's vessel so that Castiel can be free. A long, rather boring discussion of terms ensues.
Lucifer, meanwhile, shows up in Heaven to get the angels to work with him to kill Amara. Lots of talkey talk happens here, none of it particularly engrossing.
At the same time, Amara, wounded by the attack on her by the angels, gets help in her recovery from Rowena (whose inner magic has brought her back from having her neck snapped by Lucifer). But Amara soon frightens both the angels and Rowena by attacking Heaven and Rowena teams with Crowley and the Winchesters to open the cage so Lucifer can be put back in.
The most interesting part comes when the Winchesters bait Lucifer with the horn and trap him within a ring of Holy Fire and attempt to convince him to let Castiel be free. When their attempts fail, Crowley goes inside the vessel and tries to get Castiel to force Lucifer out. When Castiel says no, Lucifer attacks Crowley, who manages, barely, to escape.
When the Holy Fire burns out, Lucifer takes the Horn for himself and plans to kill the Winchesters, but Amara shows up. Based on the fact that this isn't the last episode of the season, you can probably guess what happens when Lucifer attacks her with the Horn. Yup, she survived. She captures Lucifer (and therefore Castiel as well) and frees the Winchesters. The episode ends with her torturing Lucifer, hoping to draw God out of hiding.
This episode, sad to say, was rather dull. As much as I still enjoy the show, it's starting to show its wear. The season arcs are getting more bloated and complicated and further pushing the "reality" the show established early on.
Final grade: D.