"Doctor?!" Jackie Tyler yelped, throwing open the door. "Where's Rose? Why isn't she with you? What happened, Doctor, WHERE IS MY DAUGHTER?!"
"Shh, shh, shhh," the Doctor hushed Jackie, knowing that he would not be able to get a word in until he managed to shut her up. "Rose is fine, she's alive, she hasn't been kidnapped or anything, it's alright," he said, comforting her worst fears.
"Then why are you here?" Jackie asked, still suspicious.
"I need you to do me a huge favour. I'm crossing my own timeline to do this, which is quite dangerous, but it is extremely important that this happens."
"Well, you'd best come in."
The Doctor entered the flat, wincing at the fact that it still smelt like Rose. He knew this trip was going to be difficult, but the pain of the loss still hit him like a brick wall. Jackie, thankfully, didn't notice, she was in the kitchen making tea.
A few minutes later, Jackie marched into the living room. "Explain," she demanded, handing a steaming mug to the Doctor.
"Firstly, I need to warn you, I will have to suppress your memories of this visit until they are triggered by a certain event that I know will take place."
"Wait, so you mean you want me to forget this ever happened?" Jackie asked, apprehensively.
"Yup," the Doctor confirmed, nodding slowly. "It is essential that Rose and I do not find out about our future, and I'm going to tell you stuff about yours that you shouldn't know yet."
Jackie looked confused. "So your past self is going to visit me after this?"
"Yeah. But don't worry, Rose will be with me when we call in."
"But she's not with you now."
"No."
"Where is she, Doctor?" Jackie was starting to panic again. "What's happened to my daughter?"
"It's okay. She's with you... and Pete."
"WHAT?" Jackie cried. "Pete's dead, I identified the body. Do I die to? I thought you said Rose was alive? Doctor, how can she and I be with a dead man?!"
So the Doctor told her all about the parallel universe, about Torchwood and the Battle of Canary Warf, and about how their names ended up on the list of the dead. By the time he got to the farewell at Bad Wolf Bay, Jackie's mascara was running down her face, and the Doctor's eyes were blurry.
"...then I replied, 'Rose Tyler, I...'" the Doctor sniffed, looked down, and put on a brave face, before continuing, "I never got to say it back."
"She'll never know," realised Jackie. "That's what you need me for. To pass on the message."
"Yup. I need you to give her this envelope. In it, is a letter telling her how I feel, and some photos and stuff, so she has something solid to remind her of the good times. It is essential that you pass this on, as it is," the Doctor instructed, pulling out a small but thick envelope from his pocket.
Jackie reached to take it, but hesitated. "Hold on," she questioned, "How am I supposed to know when to bring this along if I can't remember you giving it to me?"
"Your pockets. I'll place a subconscious reminder not to wear those pants until the set date, and not to check the pockets until the trigger time."
"Pockets. Got it."
"Good. you might also want to slip in a small thing of your own. You won't need money or anything, but maybe something special, a memento or something."
"Okay." Jackie ran to put the letter, along with her mother's necklace, in the jacket, before returning. The Doctor was standing up to leave.
"Oh, don't go, I haven't even told you about this nasty bloke Elton who is trying to track you and Rose down," Jackie complained.
"Rose and I'll be popping in for a chat soon, you can tell us then. I need to wipe your mind now. You'll wake up in a couple of minutes, with absolutely no memory of this. You might be a bit confused though..."
"Oh, I know, pop the telly on," Jackie suggested. "Daytime telly is dead boring, I'll think I've fallen asleep to that. Wouldn't be the first time."
"Thank you so much Jackie," the Doctor grinned.
"No, thank you. You made my daughter happy, and you're going to bring Pete back," Jackie smiled. "As much as I hate to say it, I owe you one."
"Jackie Tyler," the Doctor beamed, "I would have been proud to call you my mother-in-law." With that, he placed his hands on Jackie's temples, and locked away her memory of that visit until he appeared at Bad Wolf Bay. Leaving a snoring Jackie on the couch in front of an old movie on the television, the Doctor walked back to the TARDIS. He knew that he could trust Jackie to eventually pass on the letter, the photos, and the ring.