On Monday's season six finale of Elementary, titled "Whatever Remains, However Improbable," Sherlock Holmes (Jonny Lee Miller) and Joan Watson (Lucy Liu) have a tense confrontation, both questioning whether the other is responsible for the brutal death of serial killer, Michael Rowan (Desmond Harrington). At the moment, Watson is the FBI's prime suspect.
In ET's exclusive sneak peek, Watson -- still nursing bruised ribs -- is confronted by Sherlock, who asks point-blank: "Did you do it?"
Taken aback by Sherlock's abrupt questioning, Watson stops: "Did I do what?"
"Kill Michael," Sherlock says. "I would understand. In fact, I would do everything in my power to make sure you got away with it."
After a taking a beat, Watson finally answers his question: "No, I did not kill Michael... Did you?" Watch the exclusive clip above to see what happens next.
This season, Watson has toyed with the idea of adopting a baby, a storyline Liu says the writers came up with in order to give Watson "a personal connection" to play against.
"I think it's great. It's nice to have something personal about her in the storyline because there is a lot procedural and murders and things like that [on the show], but there is something nice about exploring that and really bringing that to life," she told ET in August. "It's a discovery of who she is as a woman and what she wants to do next. The fact that she has the ability to do that speaks to the viewers. They can look outside of themselves and see if that's something that would be of interest to them as well."
Elementary airs its season six finale Monday, Sept. 17 at 10 p.m. ET/PT on CBS.