Greetings from Lithuania.
"Chapter 52" is a brilliant ending to a terrific season 4. This is by far the best episode of the series overall (period). Everything - acting, writing, directing was a top notch - as usually, but with that "twisted" smile that makes this show unique and one of my favorite.
Overall Season 4 was a huge step up in comparison to a very good 2nd and good but inconsistent seasons 3. There were more interesting and gripping plot and twists, and reminded my of the terrific season 1 - it was that good. These two people won't let go what they have and what they want to have that easily, like one of them said "we will go one step further then any of them". That what makes this show and characters fascinating (and although sometimes they are over the top hilariously bad / twisted, but always entertaining, and plausible as possible).
Overall, do not miss Season 4 - if you liked previous seasons, you will be in nirvana watching these 13 great, great chapters.