The nuns and midwives are busy preparing for Sister Evangelina's surprise jubilee celebrations, marking 50 years since she took her vows, but a face from the past threatens to ruin the party for the guest of honour. It's back to business when a young woman with Down's syndrome is brought in feeling unwell. To everyone's surprise, they discover she is six months pregnant, causing some of them to think the worst, and the staff are joined by new nurse Patsy, whose sense of humour and no-nonsense attitude make her an instant hit.
At the DollaHyde sneaker launch party, Marty is tested by Dre and considers a double cross. Meanwhile, Jeannie learns that Lukas is suspicious of their plan; and Doug makes a fatal mistake.
With Clarkson in a Volkswagen Up, Hammond in a Ford Fiesta and May in a Dacia Sandero, the trio embark on a long road trip to the Ukraine. When the hosts arrive in Kiev, they receive a truly fearsome challenge: to complete their journey by driving through Chernobyl. Also, Jeremy Clarkson is testing the Zenvo ST, a Danish supercar with 1086 horsepower. Star in a Reasonably Priced Car welcomes back singer James Blunt, who attempts to beat his own lap time out on the track.
A violent denouement in the forest clears the Dora Lange case and turns Cohle and Hart into local heroes. Each man settles into a healthier rhythm of living as Hart returns to his family, and Cohle starts a relationship while gaining a reputation as a closer in interrogations. As time passes and his daughters grow older, Hart faces new tensions and temptations, and Cohle learns from a double-murder suspect that there could be much more to an old case than he'd once thought. In 2012, Gilbough and Papania put their cards on the table, presenting new intelligence that threatens Cohle and causes Hart to reassess everything he thought he knew about his former partner.