This is perhaps slightly worse than the Tinker Tailor Soldier Spy, but still amazing.

Some difficult points:

how did the general deduce that the old woman's daughter had a link to Karla? It must be linked to the fact that the Russian agent who made the offer was a Karla-man.
some things are hard to understand without having seen the previous Tinker Tailor Soldier Spy, e.g. they say nothing clearly who Toby Esterhase is, he now works on art sales
but others are inconsistent, e.g. they changed the actor for Peter Guillam...