A/N: Based on a scene from In the Woods, but in the TV timeline. Set between episodes four and five.

…

Rob and Cassie have been avoiding each other since the incident in the basement. Rob has heard from O'Kelly that Cassie will be going undercover for Frank Mackey, and O'Kelly isn't too happy about it. Rob is torn between being concerned for Cassie's safety and feeling relieved that they won't have to work together on the Devlin case any more. First, though, they have to interview Cathal Mills together.

The interview doesn't go well. Cathal has an alibi for Katy's murder, and he refuses to answer questions about Peter and Jamie. Rob is almost tempted to reveal who he is, just to see the look on Cathal's face. Cassie keeps shooting him alarmed looks; for once they are not perfectly in sync. They had agreed to play good cop, bad cop for this interview, but Rob is so hostile even Cassie can't smooth things over. Cathal appears to be taunting him, until Rob finally lunges across the table and grabs Cathal by the collar. He can feel Cassie's hand on his arm and throws it off him. When he looks at her there's blood on her lip from where he caught her with his wristwatch. He lets go of Cathal immediately.

"Cass..." he begins, his heart in his throat. Mills is on his feet, shouting about the complaint he's going to file against Rob, but Rob doesn't care about him right now.

"Mr Mills, you're free to go," says Cassie calmly. Cathal sneers and pushes past her, leaving her standing facing Rob.

"Cassie, I'm so sorry." He approaches her. "Are you alright?"

"I'm fine." She wipes her lip, not looking at him.

"I didn't mean to, I would never—"

"You need help, Rob." She turns away but he follows, blocking the door.

"Get out of my way." She glares at him.

"Don't go undercover," he says. "It's too dangerous. I don't want you to get hurt."

She laughs bitterly. "So you care now?"

"Cassie, please..." He reaches for her but she steps away from him.

"You need to get off this case," she says bluntly. "You're losing it."

He knows she's right, and he can only watch as the woman he loves walks out of the interview room and away from him.