to Cain, and then to Dean. As Dean says he won't pass the Mark, Death says he can relocate Dean to a place where he will do no harm if he kills Sam so he doesn't rescue him. Dean calls Sam to say goodbye and tells Sam that the world would be better without them trying to protect it, citing Charlie's death. They fight over the difference and Dean finally beats Sam. Dean then takes the Death's scythe to kill Sam. Sam manages to show Dean his importance in family and all his memories. At the last moment, Dean instead kills Death with the scythe, who crumbles into dust. Crowley brings Oskar with Castiel and Rowena, who sadly kills Oskar to complete the spell. The spell causes a lightning bolt to finally erase the Mark of Cain from Dean's arm. Rowena takes the Book of the Damned and immobilizes Crowley and Castiel. In revenge for making her kill Oskar, she casts a spell on Castiel, causing him to attack an immobile Crowley. As Sam and Dean leave the bar, lightning begins striking multiple places in the ground, causing columns of black smoke to roll into an enormous force, The Darkness. They try to leave in the Impala, only to be stuck in a pothole. The season ends as The Darkness overruns the Impala, with Sam and Dean inside. Reception Viewers The episode was watched by 1.73 million viewers with a 0.7/2 share among adults aged 18 to 49. This was a 2% decrease in viewership from the previous episode, which was watched by 1.75 million viewers. This means that 0.7 percent of all households with televisions watched the episode, while 2 percent of all households watching television at that time watched it. Overall, the tenth season of Supernatural averaged 2.48 million viewers, ranking 156th out of 188 shows. This marked a 12% decrease from the previous season, which averaged 2.81 million viewers. Critical reviews "Brother's Keeper" received acclaim. Amy Ratcliffe of IGN gave the episode a "great" 8.8 out of 10 and wrote in his verdict, "The Mark of Cain business is finally resolved. That alone is worth celebrating, but its removal had unexpected consequences with the death of Death and the unleashing of the Darkness. While it's disappointing that no one else mentioned the Darkness (like Cain), it sets up a big bad for Season 11 and the Winchesters