The statement hit both the Doctor and Rose like a ton of bricks as their delighted and proud for Martha faces dropped. The Doctor suspected worse, but decided that hopefully maybe she had been joking. "For a quick visit? Sure!"
Martha walked in slowly with a resounding and convincing, "No. For good." There was no going back now.
Rose offered, "But, Martha. No need to be rash. I mean, we left you because…"
Martha cut her off as she now was holding the consul on the opposite side of them. "I know, but I have to do this for me. No more running away chasing after dreams. I know who I am now."
The Doctor nodded soberly. "Ok, then. Next stop, London. You sure?"
Martha nodded her head holding back the tears. This was so hard for her and the Doctor and Rose could see that. She had to remain strong or this would be even more unpleasant.
Silence fell between them as the Doctor input the controls and Martha looked across at those two. As the engines pulsated a cascade of memories flowed through her head from her travels. Some with just the Doctor, some with him and Jack, and some with him and Rose. Martha had had the best of times in the TARDIS and would always remember her journey's and the people they were with for the rest of her life, but now it was over. She silently cried just thinking about how she was finally letting go. For good.
The engines died down and the TARDIS rested as Martha made her way over to her two best friends in the whole universe. "This is it. Come here you big lug." Martha smiled and hugged the Doctor with all her might as he returned it picking her up slightly in the air.
The Doctor let her down and she didn't even have to make a move as she found herself engulfed by Rose, who was crying. Martha realized she wasn't so dry herself. "Gonna miss you, Martha."
As the women broke their hug Martha glanced between them still crying. "Goodbye."
And that was that. Martha turned around and walked to the door of the TARDIS and opened it to a beautiful sunny and cloud free day outside in her time period.
Her first step was difficult leaving the TARDIS, but once both feet were out she closed the door behind her. A smile reached her lips. This was a new beginning for Martha Jones and she knew exactly what she wanted to do with her life now. That was all the Doctor's doing and somewhat also Rose's. Martha would always be thankful of the adventures and the opportunities the Doctor gave her because everything just made more sense now. The Martha she had been before had been so confused and so young, but now she could really call herself a mature adult and live a great life.
As she continued walking she pulled out her phone to call her mum. While dialing the numbers she began to hear the pulsating of the TARDIS behind her and stopped and again noticed her phone in a new light. She didn't have to say goodbye to her friends forever, so she ran back to the TARDIS screaming "Doctor, one more thing."
The winds died down and Martha threw open the doors to walk over to the Doctor who was staring at her with complete incomprehension. As soon she was close enough Martha thrust her phone into the Doctor's hands. "What?"
"That's my number right there, so if I ever want to see you again all I need to do is call myself."
Rose grinned. "Brilliant!"
The Doctor just smiled. "Well, the TARDIS already does have a phone."
Martha was surprised. "You're kidding me! Ok, well, I guess I'll just keep my phone then. What's the number?"
"Too complicated and too many firewalls to get through. I'll just keep your phone."
"I'll see you both again! Count on it!"
Martha turned and left the TARDIS for good this time while the Doctor was reminded of the future memory of Martha's concerning her strapped to a chair and the taunting of Rose being dead. They would see Martha again because that memory was certain and because of that he was not looking forward to it. Most of all, he'd never tell Rose no matter how much she stared at him suspiciously like she was doing right then. The future looked much too dark, but the present was worth keeping.
The Doctor set the phone down and input the controls to dematerialize the TARDIS as the engines pulsated and both his and Rose's frowns turned into wide grins at what was next.