John Barrowman looked at what's ahead for Malcom Merlyn's Ra's al Ghul on "Arrow," including his involvement with the Lazarus Pit and his complicated relationship with Nyssa al Ghul, during an interview with TVLine.

"All I will say to that is it's going to take a twist and a turn," Barrowman said of Meryln's relationship to Nyssa al Ghul. "Obviously, Malcolm was involved with the death of her father, so she has a bit of a grudge and she's very vocal about it. But she does something that is one of the episode's jaw-dropping moments, where people are going be like, 'Ohhhh.... Myyyy.... God.'"

Whether or not Merlyn is aware of Thea's struggle, Barrowman revealed, "He knows something is going on with Thea, that she's got this bloodlust in her, this violent streak, so he turns to her and says, 'I'm concerned about this.' But what he does with her is completely unethical and has no morality attached to it. That's again the complexity of Malcolm, that within those two situations, the audience is going to be like, 'O-M-G.' He's offering two different solutions for two different people."

"Malcolm has said before that when somebody goes into the Pit, a piece of everybody's soul who has been in there prior goes into that person," he explained. "Well, Sara's going to need a lot more than just a piece of everyone's soul. It's going to need to fill her a lot more than it did Thea, so Malcolm is very intrigued by how she might come out. But would he want her to come back when he got rid of her in the first place?"

"Malcolm's just waiting for that right moment, either to be asked or to step in -- and when one of those moments happens, again the audience is going to go, 'Oh my God, there he is!' Again, I can't tell you what's going to happen, but Malcolm will always be there when they need help," he teased.

Starring Stephen Amell, David Ramsey and Emily Bett Rickards, "Arrow" airs Wednesdays at 8 pm EST on The CW.