On Salem Season 2 Episode 11, John and Cotton started the preparations for the the exorcism on little John. As they get everything in order, little John reveals that John is his father and Cotton is seemingly not fazed by this information. Cotton has to leave the cottage for a few minutes to clear his head before diving into the exorcism. While he's outside, John is telling little John a story about his friends and about how he loved Mary at one point in his life. Things take a turn for the worse when little John starts to get agitated and tries to convince John to untie him, but thankfully Cotton shows up before anything is done and little John has a meltdown which clearly shows a demon is inside of him.
The men start the exorcism, but the demon is extremely strong and almost kills Cotton and takes hold of John. John physically throws his son against the wall and fears he may have killed him, but it's revealed little John is fine, but the demon is still inside of him. John convinces Cotton to take the boy before Countess Marburg can catch him, but Cotton hands him over to Anne who is actually Countess Marburg. Meanwhile, John is cornered by all of Countess Marburg's men, but it's Sebastian who puts a dagger in his chest and seemingly kills John.
Don't feel bad if you missed tonight's episode. You can watch Salem online anytime via TV Fanatic and experience the witch war for yourself.