The status of this story as MIA is a crying shame, since it is such a good one. "Marco Polo" contains the first seven of the missing 108 episodes. We have no censor clips, and no telesnaps for episode 4, though thankfully we have the other six episodes worth, as well as lots of other photographs. Thank goodness for fans and their reel-to-reel tape recorders, so we can at least hear the stories we would otherwise not be able to experience.
"Marco Polo" is an excellent story that is easily worth the seven episode allotment it was given. If all you care for is the quick pace of modern Doctor Who, you'll be bored stiff with the leisurely pace of stories like this one. But you'd be missing out, because the pace and length of the story manage to create the successful illusion of weeks of traveling. The longer amount of time allows Ian, Barbara, Susan and the Doctor time to get to know the people they meet and form friendships to a greater degree than they did in "The Daleks". The story is full of excellent acting, and music that really evokes a certain mood. "Marco Polo" possesses a charm that few other Doctor Who stories can match. The structure of the story reminds me of "The Lord of the Rings" in some ways. The plot takes place over the course of a long journey, with events along that journey advancing the plot and developing the characters. There's even a map to allow the audience to visualize the sequence and placement. We also have Marco Polo as a narrator, detailing events, which is almost unique in Doctor Who.
This is very much a character driven story. The Doctor and his companions want to repair the TARDIS and move on. Marco Polo wants to return home to Venice but cannot, and thus he steals the TARDIS to try and buy his way home. The warlord Tegana, the emissary of peace, is secretly planning to assassinate Kublai Khan. All of these characters and motivations, overt and secret come into constant conflict with the others and drive the plot. This makes a "journey from point a to point b" plot wonderfully complex and interesting.
Friendships play a large part in events as well, and with the lengthy time span covered by this story, there's plenty of time to make those friendships develop naturally. Susan and Ping Cho become friends rather quickly. Both are about the same age, and both are far from home, a topic they discuss on more than one occasion. I think both are glad to have someone to relate to. Ian and Marco also become friends, because despite his theft of the TARDIS, Marco is at heart a decent man. His friendship with Ian is strained by Tegana's lies, but when Marco says at one point that he thinks he knows something of Ian's character, it rings true. Ian has all the fundamental conversations with Marco, including the wonderful scene where they discuss the time traveling capabilities of the TARDIS, which Marco cannot accept until the very end after Tegana has been exposed.
The Doctor also forms a friendship with Kublai Khan, which seems to begin mainly because both are old men in pain. "Old age is a burden that must be borne with dignity." The backgammon game in which the Doctor wins half of Asia and then loses the TARDIS is a wonderfully funny scene.
As the title character, Marco Polo, played by Mark Eden, is someone who is likable from the start. He's courteous to the four travelers, and he's admirably open-minded. His travels in Cathay have allowed him to see remarkable things. He accepts that the TARDIS is a "caravan" that moves "through the air". This soon becomes a problem since he wants to return to his home in Venice, and hopes to in effect bribe the Khan he serves with the gift of the TARDIS. As an aside, if there's a pattern developing in these early episodes of Doctor Who, it is the separation of the crew from the TARDIS in one way or another. In "An Unearthly Child" the Doctor, Ian, Barbara and Susan are cut off by being imprisoned in the cave of skulls. In "The Daleks" they have access, but the missing fluid link prevents them from leaving Skaro. Now in "Marco Polo", the Venetian traveler takes the TARDIS away from them, and refuses them entry. He suffers from a guilty conscience because of this, and offers to take them home, having no idea just how far away home is for the four travelers.
Then there is the warlord Tegana. Tegana is one of the most calm and calculating villains in early Doctor Who. He is superbly acted by Darren Nesbitt. Tegana is calm and rational, rarely losing his temper. He takes full advantage of Marco's trust in him, and capitalizes on just about any mistake that the Doctor and crew make. He very nearly accomplishes his goal of killing Kublai Khan, and almost steals the TARDIS as well, since he too believes it to be a powerful "thing of magic". Listening to the soundtrack may deny me the visuals, but it allows Mr. Nesbitt's wonderful line delivery to be enjoyed without distraction.
I could go on and on, such is my enthusiasm, but I'll stop here. Do yourself a favor and get the CDs. Get the Loose Cannon recon, and watch the cut down version on the Beginning box set. Overall, another very solid story. This one comes close to being flawless. 9.5 out of 10.