Author's note: Well, someone had to take pity on them… [Warning: this chapter is almost 100% smut.]

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Chapter 10 – Undercover

It had been days, and the closest he'd gotten to Rachel was watching her through the door of the lab. She'd made the breakthrough she'd been hoping for, the breakthrough for which she'd killed Niels, but even that he had heard third hand. It wasn't that Tom Chandler wasn't speaking to him, but he certainly wasn't conveying anything but essential information, and their conversations were cold and matter of fact.

He lay on his bed replaying his last encounter with Rachel over and over. He'd told her that he was in love with her, and he was glad, but if anything it made the separation worse. He needed to know what she was thinking, how she was doing. He needed to hold her and reassure her. And if he was honest, he also needed to have sex with her. His mind drifted to the night on deck when he'd slipped his hand into her jeans and pleasured her, and as he thought about it his hand started wandering downwards, but then he stopped again with a frustrated sigh. It wasn't a worthy substitute.

Sleeping fully dressed on top of the blankets wasn't a worthy substitute for being curled up under them with Rachel either, but it was all he could manage at the moment. Constantly on alert and on edge, his temper was frayed and his body exhausted.

The knock on his door made him jump, and he moved immediately to answer it. Bacon was stood outside, and he glanced both ways down the corridor before speaking.

"XO, sir, I thought I should make someone aware that Doctor Scott's guard has fallen asleep at his post."

It took Mike a second to process the unexpected words. "And why are you bringing this to me, Cowley?" He asked, for a second genuinely confused.

"I just thought you were the person who'd, ah, benefit the most from this information, sir." Bacon replied, and nodded before heading back down the corridor.

Mike didn't even stop to put his boots on, but progressed carefully through the ship towards Rachel's quarters. When he got close, he saw that her guard had indeed dropped off to sleep, propped against the wall a few feet from her door. Moving quietly, he eased open the door and slipped through, closing it behind him. The room was in semi darkness, but as he turned a figure hurtled across the few feet between the bed and the door and landed in his arms.

He picked Rachel up, her legs wrapping around his waist as her mouth found his, kissing him passionately. He responded with equal force, pushing her back against the wall, thrusting his tongue into her mouth and his hand under her shirt, feeling for her breast. Her arms were tight around his neck, and he reached a hand under her to secure her in place, only to feel naked, wet flesh against his fingers. He swallowed a groan as he registered that she was wearing no panties, no bra, nothing but an oversized t-shirt, and without removing his mouth from hers, he managed to undo his fly and free himself to thrust up inside her, holding her against the wall as she gasped into his mouth.

There was no time for whispers or soft kisses or caresses. He thrust into her roughly, feeling her match his movements, revelling in the scent of her hair and the taste of her mouth and the tight, wet heat of her clenched around him, and before long she was shaking in his arms and biting his lip as she exploded around him, and he was stifling his urge to shout out as he came hard, holding her so tight it probably hurt, losing himself inside her for a long moment.

She slowly unwrapped her legs from around his waist, and he supported her as she slid back to the floor. Her lips were swollen from kissing, and her face was flushed, and she was smiling. He went to speak, but she laid a finger across his lips and shook her head. She pointed to the bed and beckoned him, and he followed her willingly as she pulled back the covers and climbed in. He paused to remove his pants and t-shirt, then joined her, wrapping her in his arms.

Her whisper was so soft he could barely hear it, even though their faces were just millimetres apart.

"I love you too." She said. "I promised myself that's the first thing I'd say to you."

He kissed her, gently this time, just brushing his lips against hers. Then he kissed her jaw, her cheekbones, her temple, before coming back to her mouth again.

"How are you here?" She whispered eventually.

"Cowley." He replied. "Told me your guard was asleep."

She bit her lip. "I think he guessed. When we had dinner."

"I think he did." He kissed her again; he couldn't help himself.

"He's a strange looking fairy godmother." She smiled, and he stifled a laugh. She yawned, and he did the same on reflex. "I'm so tired." She murmured. "I haven't been sleeping."

He shook his head. "Me either."

"Can you stay?" She asked.

He'd never seen her look so vulnerable, and although it was a terribly risky decision, he nodded. "Yeah, I'll stay." He rolled onto his back and she nestled her head into his shoulder, his arms tight around her.

After a few hours of the best sleep he'd had in days, Mike woke to find Rachel still snuggled tight in his arms. He glanced at his watch, then brushed his lips over her forehead to wake her, and she smiled up at him sleepily.

"They're going to expect you to leave for the lab soon." He whispered. "You can't be late, they mustn't check the room."

She nodded and stretched up for a kiss. He meant it to be brief, but the feel of her soft body in his arms, the warmth of her lips, the smell of her hair, all combined to make him deepen the kiss and roll her onto her back. She put her own hand over her mouth as he pulled the t-shirt – one of his, he noted – over her head and moved down to kiss her breasts, licking and sucking her nipples as they hardened, feeling her arch into his touch. Keeping his mouth on her breast, he reached a hand between her legs, stroking gently and sliding a finger inside her as he circled his thumb on her sweet spot. She jerked slightly and he smiled against her skin, pressing more kisses over her breasts as he continued to caress between her legs. When she came it was with a slow shudder of pleasure and the very faintest moan.

He raised his head, but before he could move she was pushing him back into the thin mattress, moving over him, her lips tracing across his chest, following the line of hair down his stomach, and suddenly her tongue was circling the tip of his hardness and he was the one clapping a hand over his mouth to prevent a sound escaping as she closed her lips around him and slid down, enveloping him in her warm, wet mouth. If it hadn't felt so damn good, he might have been embarrassed by how quickly she brought him to the edge, her fingers lightly stroking his balls as she sucked him hard, and then before he knew it his hips were moving involuntarily and he was thrusting upwards and coming in her mouth.

By the time he managed to unclench his teeth and open his eyes, she was face to face with him, her smile one of entirely naughty satisfaction.

"Oh, I enjoyed that." She whispered, and kissed him.

He let out a deep, somewhat wobbly, breath. "I definitely didn't hate it." He replied, and he saw her try not to laugh. He stroked her face. "You have to go."

She nodded. "I know."

They dressed in silence, and Mike positioned himself behind the door as she went to open it. Just as her hand touched the handle she hesitated, and took a quick step back into his arms. He held her tightly and dropped a last kiss on her mouth.

"I love you." He breathed into her ear, and she nodded.

"I love you too." She murmured, and then she was gone.