Both Howards continue to search for answers behind the killings in the next episode of “Counterpart.”

According to the synopsis for Season 1, episode 4 of Starz’s sci-fi thriller, Howard Prime and Howard Silk (both played by J.K. Simmons) deepen their investigation of the conspiracy.

In the last episode, Ambassador Claude Lambert (Guy Burnet) revoked Prime’s visa. But because Prime suspects that Lambert is working with the group responsible for the string of murders, Prime insisted to stay on our side of the wall to continue his investigation, and suggested to send his counterpart, Silk, to his world so no one would notice that he hasn’t come back yet.

Prime said at the end of last episode that Silk has to stay in the other side of wall for at least a week or until Prime can find away to unfreeze his visa. “You want me to inhabit your life?” a shocked Silk asked Prime after hearing his idea. Prime pointed out that it’s actually “the last thing in the world” he wants. But apparently, he doesn’t think they have other choice.

When Silk told Prime that he couldn’t just leave his wife, Emily (Olivia Williams), at the hospital, Prime made Silk realize that she would have been dead right now if Prime didn’t cross to the other side. “How long you think she stays alive if I go home?” Prime asked Silk.

In the trailer for the next episode, Silk doesn’t think he can pull off the plan. “They’re gonna see through me,” a worried Silk told his counterpart.

“Not if you keep your mouth shut,” Prime says.

And that’s exactly what Silk does when he bumps into Ian (Nicholas Pinnock) at the hospital in a sneak peek from the episode. In the minute-long clip, Ian is surprised when he sees Prime inside Emily’s hospital room. “There’s some reason you’re here Howard?” Ian asks Silk who he thinks is Prime. “Thank you for coming. [But] I’ve got it.”

When the two guys get out of Emily’s room, Ian starts to ask questions and make accusations. But Silk doesn’t utter a single word as advised by his counterpart.

Elsewhere in this week’s installment, Quayle (Harry Lloyd) meets one of Prime’s sources, and Clare (Nazanin Boniadi) must decide what to do about Baldwin (Sara Serraiocco).

“Counterpart” Season 1, episode 4, titled “Both Sides Now,” airs on Sunday, Feb. 11 at 8 p.m. EST on Starz.