BritBox's excellent collection of the Hartnell era runs into a snag--the story collectively known as Marco Polo no longer exists. So, yeah, as they euphemistically put it, "unavailable," and who can blame them?
Fortunately, as the rather good reconstruction embedded above demonstrates, that doesn't leave us entirely without expedients. Reconstructions take one of two forms--new animated efforts to overlay the still-extant soundtrack (preserved by fans taping the shows as they aired!)or using the "tele snaps" that were taken during filming to create a sort of montage that captures something of the feel of the original.
It's an aesthetic choice, but I prefer the photographs. Seeing Ford, Hartnell, Hill, Russell, and the guest cast is meaningful to me in a way that a cartoon of them would not be. So--we continue:
There's an absolutely lovely moment in "The Roof of the World" that is the most "Doctorish" I have seen Hartnell to date. The situation is dire: after the brief moment of happy camaraderie that ended The Brink of Destruction, things go agley--another TARDIS component is broken, depriving the travelers of heat, the mountain is so high that it lacks air enough for the Doctor to function, and night is closing in.
Rescue has come in the form of Marco Polo and his caravan, on his way to Kublai Khan, along with the warlord regina, who, in defeat, is come to make peace. Reluctantly, and still looking for a way to reverse his defeat.
Anyway, Marco, who wants to go back to Europe, decides to give the Doctor's "flying caravan" to the Khan, to barter for his freedom. The Doctor sputters in outrage and betrayal at his erstwhile rescuer:
POLO: I intend to. This time, I shall offer him a gift so magnificent that he will not be able to refuse me.Marco sweeps away, and Barbara helps him to a chair.
IAN: You mean to give the Doctor's caravan to him?
DOCTOR: You're mad.
POLO: You can make another.
DOCTOR: What? In Peking, or Shang Tu?
POLO: You do me an injustice, Doctor. I will not leave you stranded in Cathay, just as I did not let you die on the mountain. No, you will come with me to Venice and make another one there.
DOCTOR: Oh, you think so, really? Oh no. Oh no.
IAN: Marco, it's impossible.
POLO: Surely, for a man who possesses a flying caravan, all things are possible?
IAN: No. We need special metals, materials, things that don't exist in Venice. I'm afraid you don't understand all the problems involved.
DOCTOR: And neither do you, young man.
POLO: Well, travel home by ship. We trade with every port in the world. It may take you longer, but you'll get there eventually.
DOCTOR: Eventually. He doesn't know what he's talking about. The man's a lunatic. Ho.
POLO: No, Doctor, desperate. There are many men who are jealous of the Polo influence at court, and the Khan suffers from an affliction for which there is no cure.
BARBARA: What's that?
POLO: Old age. If he dies, I may never see Venice again.
DOCTOR: Well, that is your problem, not mine.
POLO: I have just made it yours, Doctor.
BARBARA: But you do see Venice again, Marco, I know you do.
IAN: What makes you so sure that the Doctor's caravan is a suitable present? The Doctor is the only one who can fly it.
POLO: I told you about the Buddhist monks. They will discover its secret. A caravan that flies. Do you imagine what this will mean to the Khan? It will make him the most powerful ruler the world has ever known. Stronger than Hannibal. Mightier than Alexander the Great.
IAN: Marco, you don't understand.
POLO: I refuse to listen you to any more. My mind is made up. Your caravan goes with me to Kublai Khan.
And then--the Doctor laughs. Not hysterically, but just at the ridiculousness of it all--how can he explain to Marco Polo why "returning" to Europe won't allow him to build a new TARDIS? The multiple leaps of cognition the explanation would take--he guffaws, he wheezes with laughter. He's frustrated beyond bearing, but can't help but see the funny side of it all. And Hartnell nails it. It's the best long sustained laugh this side of Leo McKern in "Fall Out":
DOCTOR: Oh well, what a mess.It's a moment Tom Baker could have brought off, and maybe Matt Smith, but it's all Hartnell.
SUSAN: Grandfather. Grandfather.
DOCTOR: Yes. Go by sea, he says.
SUSAN: Why are you laughing? He means it.
BARBARA: Doctor, he's serious.
DOCTOR: I know he is. Yes.
SUSAN: What are you going to do?
DOCTOR: [overcome with laughter] I haven't the faintest idea.
The rest of these three episodes feels rather like a Tom Baker era story, albeit of the slightly "meh" variety. Susan makes a friend, Ping-Cho, who is being brought to the Khan's court to marry a 75 year old man (hmm...that's the Khan's age...) Tegana plans to kill Polo and seize the TARDIS, and Susan and Ping-Cho get caught in a sandstorm. But they're ok. Except Tegana has cut the water gourds, and we're in the middle of the Gobi Desert too--and the Doctor has fixed the TARDIS, but they-
Oh, forget it it. Look, it's simple: Tegana is out to kill Kublai Khan, and thinks he can use the TARDIS together. Like a 13th Century Wile E. Coyote, he keeps setting traps for (1) The TARDIS crew; (2) Marco Polo; or (3) both. So far, none of them has erupted.
Yeah, it's a traditional runaround, my least favorite aspect of Doctor Who.
One nice moment again--the Doctor dresses down Marco, deriding him as "You poor, pathetic, stupid savage." His laugh now is cutting and scornful. There's a lot of fat in these episodes, but there's good stuff too.