After what had been quite a climb, the two arrived at the top of the enormous stair mountain. Before them was a magnificent castle-like structure encased in a transparent bubble.
Martha noticed, however, that there appeared to be no point of entry. The clear, glass walls seemed to her quite solid. Before she could bring this up, however, the Doctor was already working away, feeling along the sides and occasionally whipping out the Sonic Screwdriver, muttering all the while.
“If I could just remember how to get in…” he murmured, his brow furrowed. “Let’s see…what was it…three to the left and…six down? Or was it seven?”
Martha remained silent, knowing it best to keep her mouth shut when the Doctor was in this kind of state.
“Wait a second…here it is…aha!” the Doctor cried triumphantly. His thumb on what appeared to be the correct location, he scanned it with his Screwdriver.
“Welcome to the Time Lord Citadel,” said a female-sounding computer’s voice. “Please state your Identity.”
“The Doctor,” he replied confidently.
Nothing appeared to have changed. “Second request,” said the computer, “Please state your Identity.”
“Oh, that’s right…we’ve switched to ID numbers now, haven’t we? Those prawns.” The Doctor cleared his throat. “Time Lord Nine-Five-Six-Zero-Four-dash-Eight,” he said, with clear difficulty remembering.
“Identity: Affirmed,” said the voice. “Welcome to the Citadel.”
For a second Martha thought that the bubble was going to collapse as it gave a great shudder similar to that of an earthquake, but instead, a door-sized opening appeared to melt out of a small, rectangular section of the glass. The team let out a cry of triumph.
The Doctor had to duck in order to pass through the threshold. “Those other Time Lords,” he said, shaking his head, “they’re all so damn short…come on, Martha!”
Still grinning, Martha passed through the doorway. Almost immediately thereafter, several alarms began to shriek around them.
“Non-Time Lord detected at entrance,” stated the computer’s voice calmly, “All officials please report to the front of the Citadel. Non-Time Lord detected…”
“What?!” cried the Doctor.
The Blue Box: 
What happened? How come you’re not writing anymore? Hope all is well.