This is one of my favourite stories of all time. Two issues: one is that the plot does feel a bit like it was written by two people who didn't entirely agree on the direction of it (because it was); the other is a technical one, which is that it's nearly impossible while listening to it (being missing and all) to keep track of which character is which. They've all got similar names and voices.
But episode 4 of this, bar the dismal final flourish where Dodo is introduced, is one of the greatest episodes of the entire programme.