Rose reluctantly opened her eyes. The handset to the baby monitor was flashing a blinding green light in their pitch-dark room. Jack's cries rang through the monitor. She didn't feel like getting up to tend to him this time, so she blindly felt next to her to see if the Doctor was there tonight. Even though he was half-human, he had retained the need for considerably less sleep than Rose. She felt so jealous of him sometimes, especially now that they have a newborn baby boy who wakes up every two hours at night. The Doctor, ever the doting father, was happy to take care of nighttime care, learning how to swaddle, change diapers, and bottle-feed Jack pumped breast milk so Rose could catch up on her well-deserved sleep. She still woke up most times, if Jack made the slightest noise, but nine times out of ten the Doctor would take care of it before Jack got too upset.
Rose noted her husband's empty spot in their bed, and she groaned, preparing to get up. Before she could sit upright, she heard faint talking coming from the monitor. She recognized the Doctor's voice, but she couldn't make out very much of what he was saying, so she picked up the monitor and held it closer to her ear.
"…remember this song, eh Jack?" The Doctor laughed softly and began singing. The song was familiar, but the words were foreign. Rose was sure she had heard it before.
"I used to sing this to you when you were still in your mum's tummy."
Rose could hear the smile in his voice over the monitor. The Doctor's song resumed, and soon Jack's crying subsided. She smiled – of course she had heard it before! The Doctor would sing to her swollen belly when she was painfully pregnant; the song would lull her to sleep within a matter of minutes despite the throbbing pain in her back.
The Doctor's song reduced to a low hum, and Rose got up to stand at the doorway between their bedroom and Jack's nursery. The Doctor had Jack's nightlight on – a beautiful glass light that projected realistic constellations and nebulae onto the ceiling and walls ("He's gonna see space eventually anyway, Rose, might as well get him used to it") – and he was gently bouncing Jack in the crook of his arm. Rose watched as Jack slowly closed his tiny eyelids and drifted off to sleep in his father's arms. The Doctor smiled, looking down at his son as if he were the most precious thing in the entire universe – and to them, he was. Gently he placed Jack back down into his crib and turned around to see Rose.
"What kind of song was that?" Rose spoke just above a whisper until the two of them went back into their bedroom. "I know I've heard it before, but I can't understand it."
The Doctor lay next to Rose, stretched out on the bed with his arm around her. "It's a lullaby. I used to sing it to my kids and grandkids back on Gallifrey, a long time ago. It was specifically written to make whoever is listening go to sleep." He chuckled. "Probably one of Gallifrey's greatest gifts to parents."
"It's too weird to think about you having grandchildren," Rose mused.
"I know, the aging process in this body is barely twenty-eight or twenty-nine years old, isn't that what Owen said? I just want Jack to know the language, is all."
"When are you going to teach me, Doctor? You promised me not long after you came back that you would teach me, so we could write notes and stuff to each other and no one else would know what it says." Rose knew it sounded like she was whining, but it had been three years since he returned and she was growing impatient.
"How about we start tomorrow? Get some sleep, rest up, and we'll start with the alphabet first thing after tea."
"Okay." Rose smiled up at him, and he kissed her on her forehead.
"Now go to sleep, my love. I'll see you in the morning."
Rose fell asleep seconds after the Doctor left their bedroom, and she dreamed about swirling circles and beautiful melodies, red grass and silver trees, and a beautiful baby boy with his hair and eyes smiling up at her.