OK so like most of these excellent TV drama series, the last couple of series lose it a bit, go a bit OTT, like Breaking Bad and more. It gets increasingly unbelievable - though of course it is fiction, though maybe based on facts, and I watch it as such. Sometimes it just jumps the shark a bit in this series, I think. The first 3 series are the best.
However, even as a 4/5 scoring series it is streets ahead to the very inferior drama available on the BBC and UK TV.
The actors are great - the Welsh actor Matthew Rhys in the lead and his wife, and the FBI staff.
The dramatic tension is maintained with WILL THEY/WON'T THEY be found out - so just the same as with BREAKING BAD. It lags a tad in later series but this is still fine drama.
Love the 80s music too!