I might be any number of things... Picture

The Doctor has collapsed onto the floor of the Tardis control room. His two companions, Tegan and Turlough, are kneeling over him.

Tegan: "He's only just about conscious."

Turlough: "If only he'd managed to send that signal."

Suddenly the main doors open and two figures enter. One is an elderly gentleman with long white hair dressed in a black frock coat with check trousers, the other is a young woman with dark curly hair wearing a long raincoat.
The young woman crosses to the center console and without hesitation operates the correct control to close the doors.
The Doctor's two companions both rise an stare in astonishment at the intruders.

Tegan: "Who are you?"

The old man's reaction is completly unexpected.

Stranger: "More to the point, what are you young people doing inside my Tardis?"

Tegan points angrily at the Doctor, still lying on the floor.

Tegan: "It's HIS Tardis."

The old man glances at him.

Stranger: "And who might he be?

Turlough: "The Doctor."

The old man stares at the figure on the floor with renewed interest.

Stranger: "Hmm? ...Good grief!"

The Doctor's eyes flutter open and he stares up at the old man.

Doctor: "You're here... you're here."

Stranger: "Yes, evidently."

The old man reaches down to assist the Doctor to his feet.

Stranger: "Now take it steadily, my boy, and let me help you up."

The Doctor's strength, which had almost failed him, seemed to return the moment the stranger touched the Doctor's hand.
It also became apparent that the Doctor knew the white haired intruder and was pleased to see him. This served to calm Tegan's rising temper, for a little while at least.

Doctor: "I tried to send a recall signal."

Stranger: "Yes, it doesn't matter. How do you come to be here?"

Doctor: "Well the Tardis was..."

The Doctor frowned as his memory failed him.

Doctor: "I don't know."

Stranger: "Never mind that."

The young woman, who had been staring at the Doctor ever since Turlough had spoken his name, spoke: "Is he really..."

Stranger: "Me? Yes."

The smile that accompanied these words failed him and was replaced by a frown.

Stranger: "Yes, I'm afraid so. Regeneration?"

Doctor: "Fourth."

Stranger: "Goodness me! So there are five of me now!"

The old man noticed that the stare his companion had been giving the Doctor was now being returned.

Stranger: "Oh, this is Susan."

The Doctor smiled.

Doctor: "Yes, I know."

Susan smiled back.

The old man obviously feeling the need for futher introductions turned to the Doctor's two companions.

Stranger: "And, you two are...?"

Turlough: "Turlough."

They shook hands.

Tegan: "And I'm Tegan Jovanka."

Tegan held out her hand and smiled as the old man shook it.
She then raised her eyebrows at him.

Tegan: "Who might you be?"

Stranger: "I might be any number of things, young lady."

He looked her straight in the eye.

Stranger: "As it happens, I am the Doctor. The ORIGINAL, you might say."

The First meets the Fifth.
The Five Doctors by Terrance Dicks
Doctor Who (c) BBC

The Doctor - Peter Davison (5th) & Richard Hurndall (1st)
Tegan - Janet Fielding
Turlough - Mark Strickson
Susan - Carole Ann Ford

The Five Doctors was broadcast on the 25th November 1983 to celebrate 20 years of the show. It is unique in that it is the only feature length story to be created during Doctor Who's original run of 26 years. In fact in the show's 49 year history the only other feature length story was the Paul McGann TV Movie.

Many fans regard this as one of the great missed oppertunities as Tom Baker declined to take part. The fourth Dcotor, using scenes from an untransmitted story (Shada), was kidnapped at the start - held in stasis - and returned at the end.

Patrick Troughton is flawless as the second Doctor who, accompanied by the Brigadier (Nicholas Courtney), fights off an attack by a Yeti and thwarts an attempt to trick them using the images of his friends Jamie and Zoe.

Jon Pertwee is as stylish as ever as the third Doctor, first rescuing Sarah Jane Smith (Elisabeth Sladen) then confronting the Master (Anthony Ainley) and finally watching as an unstoppable robot destroys a platoon of Cybermen.

The sad death of first Doctor William Hartnell left a hole that would be filled in this case by Richard Hurndall. Joined by the Doctor's granddaughter Susan (Carole Ann Ford) they manage to destroy a lone Dalek before meeting the fifth Doctor (Peter Davison). The first Doctor leaves in the company of Tegan (Janet Fielding) and also encounters the Master and even more Cybermen.

William Hartnell himself appears in a clip that precedes the opening titles and is taken from The Dalek Invasion of Earth. The speech, which is part of his farewell to Susan, begins with the appropriate words "One day I shall come back."
You can find the full speech in one of my other deviations "Goodbye my dear" (Sorry I'm no good at links
Continue Reading: Figures