At a gathering of former companions of the Doctor, Melanie Bush asks, “How many Doctors are there?”
How many might they be able to figure out?

ROLL CALL:
Ian Chesterton, companion to the First Doctor.
Jo Grant Jones, companion to the Third Doctor. Met First and Second, knew their order. Met the Eleventh, who told her the Tenth looked them all up.
Tegan Jovanka, companion to the Fourth and Fifth Doctors. Met First, Second, and Third. Knew First was the original and heard there was one other (Fourth).
Melanie (Mel) Bush, companion to the Sixth and Seventh Doctors.
Ace, companion to the Seventh Doctor.
Kate Stewart, UNIT director. On screen, met the Tenth, Eleventh, Twelfth, Thirteenth, and War Doctors. Jo, Sarah, Tegan, and Ace all knew her father.
Graham O’Brien, companion to the Thirteenth Doctor. Met Fugitive.
Dan Lewis, companion to the Thirteenth Doctor.
Yasmin Khan, companion to the Thirteenth Doctor and Doctor-as-Master. Meet Fugitive. Knew Thirteenth was about to regenerate.
And there appeared to be a laptop on a chair. Someone else Zoomed in? Many fans want it to be Sarah Jane Smith.

KNOWN DOCTORS:
So which Doctors do these folks know about?

First – Ian was his companion. Jo and Tegan met him.
Second – Jo and Tegan met him.
Third – Jo was his companion. Tegan met him.
Fourth – Tegan briefly traveled with him before his regeneration.
Fifth – Tegan was his companion.
Sixth – Mel was his companion.
Seventh – Mel then Ace were his companions. Up until the Seventh, they could figure out the order of Doctors.
Eighth – Kate probably knows because UNIT had a photo of Grace, but she may not know his number.
War – Kate met, may not know his order.
Ninth – Kate knows through UNIT, but she may not know his number.
Tenth – Kate met. Sarah Jane and Eleventh each mentioned him generally to Jo.
Eleventh – Kate and Jo each met him.
Twelfth – Kate met. Yaz heard the previous self had been a white-haired Scotsman. Graham heard mentions but thought she was joking.
Thirteenth – Kate, Tegan, and Ace met her. Graham, Dan, and Yaz were her companions.
Doctor-turned-into-Master – Yaz defeated him.
Fourteenth – Yaz knows Thirteenth was about to regenerate. Even if Kate has photos, she may not realize this is a different Doctor.
Fugitive – Graham and Yaz met. Her order is unknown, even to the Doctor.
Valeyard – Mel encountered him.
Curator – Does Kate have any reason to suspect?
Merlin – Ace knows that a later Doctor would be Merlin.

If Kate won’t share top secret information, they may not know anything about Eighth, War, and Ninth. She might entice by saying she can share with consultants who’ve signed NDAs. Farewell, Sarah Jane indicates that Sarah’s death is still in the future. If Sarah Jane Smith is the one on the laptop, she can tell them more about the Tenth Doctor. She also knows he had regenerated “half a dozen times since we last met” in The Five Doctors. On screen, she met seven doctors (first five, Tenth, Eleventh).

Audio dramas make it too easy for them to fill in the gaps.