Channel 4's The Adulterer - we seem to be missing a season, any idea where to find it please?

[ARudeTerriblePerson]

We loved Series 1 and 2. Now Series 4 seems to be available, but we can't find Series 3. Any ideas?

Oh, come on, you must all be fans!

I have never seen this but the title looked interesting so I had a look, on Sky Go I found only season 3, none of the other seasons, on All Four I found seasons 1-3 but no season 4, are you in the UK. I am going to start watching this so thanks for bringing it to my attention.