So this was just a fluffy little idea my brain had. There is an already established Master/Jack relationship, The Master is cured of the drums and the two of them are traveling with The Doctor. Jack has been having nightmares about Gray and the events of COE and hasn't slept.
Jack lay on his back in the hammock the TARDIS had provided him. The astronomy room. He spent a lot of time here anymore as it was the only room on the ship where he could, for lack of a better term, space out. He would spend hours just looking up at the stars of whatever part of the universe they happened to be in. Footsteps on the winding stairwell caught his attention and he looked over to see The Master. As his foot hit the top stair he caught sight of Jack and froze, one hand in the pocket of his black hoodie and the other on the railing. The blonde made to turn, apologizing for bothering him, and head back the way he'd come.
"Wait," Jack called, reaching one hand out toward the Time Lord. He paused to look at Jack again. "You don't have to go. You can stay if you want to." He watched as tense shoulders went lax and both hands were stuffed into black pockets. Amber eyes stared at Jack in the awkward silence. "You haven't been sleeping," he stated, crossing the room in three strides to the side of the hammock. "How long has it been?" Jack looked away shyly. "About a week and a half." The Master huffed at him. "You need to." A calloused thumb brushed gently over the purple ring beneath his eye, leaving a warm sensation in it's wake. "Insomnia's not a good look for you."
"Yeah, well." It was quiet again, the pair just looking into each others eyes. The Master was looking deeply into the pools of blue, seeing the weariness and pain in them. "That's it. Make room," he ordered, waving Jack to one side of the hammock. Jack shifted as much as he could while being careful not to flip the thing and The Master climbed on beside him. He looked at Jack, snatching the pillow from beneath the immortal's head and slipping it under his own. "Hey," he protested. "You could have just asked for one of your own."
"Hm-mm. S'mine," he mumbled, patting his chest. "This one's yours." He didn't give Jack a choice, curling an arm around his shoulders and pulling him close. Jack just smiled, shifting to a comfortable position. When his lover finally settled, the Time Lord dropped one leg over the edge to touch his toes to the floor and push off, starting them rocking. They just lay there for awhile, swinging in silence. Then Jack heard something he thought he'd never hear in a million years. The Master was singing. It was like nothing Jack had ever heard before, low and lilting and gentle. "What is that," Jack asked. "It's a Gallifreyan lullaby. My mother used to sing it to me until I went off to the academy," The Master answered. Jack nestled his head further into his lover's chest. "It's nice."
"Well, I can't be seen in public with you looking like a raccoon, now can I?" However, the Time Lord's free hand reached up to take hold of the one resting on his chest, a gesture Jack knew was the other man's way of saying 'but mostly I'm worried about you.' He smiled, pressing a kiss to his lover's neck before settling back down as The Master picked up where he left off. It wasn't until the blonde had taken his hand that Jack had understood what was happening. For the first time in over a millennium, Jack was being rocked to sleep. He reveled in the surge of comfort that realization gave him but he couldn't allow himself to fall asleep yet. "Master?"
"Hm?"
"...will...will you be here when I wake up?" The Master grinned and squeezed the immortal's hand gently. "So what happened to not wanting to see me?" To be honest, Jack wasn't sure why he'd changed his mind. "You know why I said that. With the nightmares I've already been having I didn't need the Valiant tossed in there too."
"Thought you'd forgiven me for that," the Time Lord pouted. Jack smiled at the rare display of childish behavior. It was adorable. "And I have," he explained. "But it doesn't make the memories any easier to deal with. Anyway, I guess I didn't realize how much I wanted to see you until you were already here if that makes any sense."
"Not a bit," The Master said. "Now shut up and close your eyes." Jack looked up at his lover expectantly. He still hadn't gotten his answer. "Like I've got anything better to do," he huffed. His proud way of saying 'I'll stay as long as you need me to.' Jack smiled, settling in once again and finally letting his eyes slip closed. For the first time in over a week, the captain slept. There were no dreams of the brother who had buried him under a city or the aliens that had forced him into that terrible, fateful decision. Instead, he dreamed of a tall, freckled boy called Koschei who took him by the hand and led him through a field to lie in the lush, deep red grass and look up at the burnt orange sky. The mountains went for miles and the leaves on the trees were a brilliant silver. The boy reached over and threaded his fingers through Jack's and Jack squeezed back. It was beautiful, magnificent, and he realized, the place The Master had called home. He smiled. Leaning in, he pressed a kiss to the young Time Lord's forehead. "Thank you." The young version of The Master turned his head in the grass to look over at him. "For what?"
"For sharing this with me," Jack smiled, brushing his thumb against the back of the other man's hand. He thought for a long minute, debating whether or not he should say what he was thinking. Finally, he moved in closer to Koschei, lips a breath away from his ear and whispered. "I love you."
xXxXx
The Master's eyes went wide, still swinging with his sleeping lover tucked safely in his arms. He'd never been good with emotions but now the other man had put it out there. He sighed. Why did human's have to say everything? His feelings should be obvious. He was here wasn't he? Cheeks tinged pink, he kissed the top of the sleeping captain's head and whispered those four little words, muffled by his lover's hair but he knew the man had heard him. They stayed there for hours, The Master rocking and singing and Jack sound asleep with the most contented smile anyone had ever seen. The two didn't even notice the flash go off. The Doctor smiled, heading down the stairs with the camera still in his hands. "Just for posterity," he grinned, heading back to the control room.