When the Doctor returned with the coffee things were stiff and formal between him and Jack. There was only so much small talk that the Doctor could make. He already knew how Jack took his coffee, so they couldn't talk about that, and any suggestion made about food was cut off with a quick "no thank you," which rather limited the conversational possibilities on that front as well.
In lieu of distracting himself by the conversation, the Doctor attempted to do so by studying Jack. The tremors were gone. Jack was thinner than he'd been when they'd traveled together, but all in all didn't look terribly different. The man had aged, but only slightly. A few gray hairs, some wrinkles. If the Doctor hadn't known better he'd have thought five or maybe ten years had passed since they'd seen each other last. But given Jack's unusual nature he knew that wasn't the case. It hadn't been that long for him, but he couldn't help but wonder how many years had really passed for Jack. "How old are you, Jack?" he finally asked, blurting out the question before he could stop himself.
Jack looked up briefly, before focusing back down on the mug between his hands. "Kind of hard to say, isn't it? I suppose it depends. Everyone looks at time differently, don't they? We talking lunar cycles of Trylos Seven? Harvest celebrations of Dendrax? Human standard years? Considering you know I don't get older, well, not really, not the way normal humans do, I can't help but wonder what you're really asking. How long has it been for me since I've seen you last? Or do you mean how long I've been here?"
If the Doctor was surprised by the flat tone Jack used, he didn't comment on it; all he said was, "Your age. Human standard years."
Carefully draining his coffee and putting down the empty mug, Jack stood up and walked over to his belongings. "Far older than you will ever be. Probably older than any Time Lord could ever hope to be, would ever want to be." After digging around amid his things for a moment Jack pulled out the small wooden box the Doctor had noticed earlier. He touched a hidden latch and a secret compartment sprung open. He palmed what fell out and then slid the compartment shut, putting the box back in his satchel. "Got this when I became a Time Agent," he began carefully, "although it's seen better days." He paused for a moment, holding it tightly within his grip before opening his hand and holding it out for the Doctor to see. "Recognize it? My vortex manipulator. The strap's long gone, the cover too, but the majority of the circuitry is still sound. And, if I'm remembering this right, it should..." Jack trailed off as he hit a few buttons, trying to find the information he wanted. "See for yourself." He tossed it to the Doctor. "Standard years since activation. Probably not entirely accurate, but should be close."
The Doctor caught the manipulator carefully, not wanting to risk breaking something that meant so much to Jack. He simply stared at the data for a moment before muttering, "This can't be right."
"Why not? Because you don't want it to be? Sorry, Doctor, things don't work that way in real life."
"But, Jack, according to this your vortex manipulator came off the assembly line more than twenty-seven thousand standard years ago. You, you can't be," he looked up seeking the truth in Jack's eyes but unwilling to accept what he found there, "That's impossible."
"And here I thought you used to believe in the impossible. I always pictured you a bit like the White Queen in Through the Looking Glass, believing in six impossible things before breakfast." Jack tilted his head, lost in thought for a moment. "I wonder if that makes me Alice. There are worse things than that, I suppose, and being with you was always an adventure. Although, not always in Wonderland."
The Doctor couldn't help but notice the smile that flickered on Jack's face for a brief second before reality came crushing down. "But it wasn't all bad, eh?"
"No." Jack held his hand out, motioning for the Doctor to pass the manipulator back. "Not all bad." Walking over to his things he pulled out the box, reopened the compartment, and put the manipulator away. "We did have some good times. Hell, we had some great times." Jack studied the Doctor for a moment. "I know what you want from me, Doctor. You want me to soothe your conscience. You want me to tell you I'm fine with what just happened here, and what happened all those years ago and that I want to take off in the TARDIS with you so we can explore the stars together. But I can't. Not yet anyway. I'm not ready, and be realistic, neither are you."
"But, Jack..." the Doctor began, only to trail off when Jack raised his hand.
"I agreed to stay for coffee, Doctor. And we had our coffee. Now you need to let me go. Let me walk out those doors with my head held high. It doesn't have to be goodbye for forever, but I need to move past this point, this place where I am in my life. And we've got time." Jack picked up his things and moved out of the medical bay. He paused briefly in the doorway, but didn't turn around. "Give me some breathing room. Travel about for a bit and come back for me in ten standard years' time. I might be ready then."
And with that he was gone.
The Doctor sat there, staring at the empty coffee cup in his hands, and didn't move for a very long time.