Sherlock (Jonny Lee Miller) fears that he might be locked up in prison for the attempted murder of Oscar (Michael Weston) in the upcoming season of the CBS series "Elementary."

In a trailer released by the network, the sleuth is seen confessing to Joan (Lucy Liu) his worry of getting stuck in jail. Sherlock, who had a drug relapse in the last installment's finale, nearly killed Oscar due to frustration. Now that his sanity is quite back, he is afraid that Oscar may be sending the police to capture him.

Joan, for her part, assures Sherlock that it will not happen. However, she also promises that if he will indeed be imprisoned, she will be willing to join him behind bars. Joan then tells Sherlock that the only thing that matters to her is their partnership, and if one of them has to go, she will also. She then gives him a hug, as if to tell him that everything is alright.

Meanwhile, also seen in the trailer is the arrival of Morland (John Noble). Upon reaching New York, Sherlock's dad surprised his son, who does not look like he is thrilled to see him. Apparently, so is Joan, as she is heard warning Morland that she will not stop Sherlock if ever he decides to hurt his father.

Series executive producer Rob Doherty has previously revealed to Entertainment Weekly that there will be "some friction" between Joan and Morland when they finally meet each other in season 4.

"When Morland arrives and makes a genuine and surprising attempt to help Sherlock, Sherlock has to rethink his relationship with his dad. But as the season progresses, we're going to see that Joan is worried that dad is a little more like the guy Sherlock has described versus the guy he seems to be now. She'll be keeping a careful eye on him," said Doherty.

"Elementary" season 4 will premiere on Thursday, Nov. 5, at 10 p.m. EST on CBS.