I'm not going to review the overall story here; but instead where I think the novel differs from the TV version of the story (as far as we can tell). I enjoyed that version a lot; but I think the novel overall falls short.

The improvements are that it does a very good job at making this adventure feel a lot larger - the narrative gives timescales; and things like giving bigger description of distances and even the meals that the travellers eat helps to add to the scale of this story (even if I wonder how authentic they'd be to that period of China). The story already stands out on TV for being this big adventure across Asia without the TARDIS being available; the context of it clearly lasting several months I think adds to the scenes where the TARDIS crew try to escape. The scenes with the Doctor and Kublai in the book also feel more sensible than those in the TV because of the fact that they had more time.

However there are a couple of areas where I think this story falls short. The characterisation of the Doctor feels off - it almost feels like Lucarotti is writing for a much more modern version of the Doctor than an early First Doctor so certain elements (like him being so keen to help out Marco at points; or even his not accepting the key back in the final chapter because he lost the Backgammon game) feel very weird for the context of the story. Indeed it also hurts Ian's role in the story - as the Doctor takes a large portion of his role in the novelisation and that feels like a negative. The ending also comes across less well - rather than Tegana committing suicide because his regicide attempt was foiled, he's instead killed by Ling-Tau who plays a much greater role in the novel becoming Ping Cho's fiancé by the end; and rather than a hurried escape its a more formal thing which I think doesn't make as much sense.

Overall though I think this is a decent read - although the negatives detract from this a lot more than the positives add.