Neil Oliver visits Reichskrone, the Imperial Crown of the Holy Roman Empire, in Vienna and discusses how Cnut the Great's attendance of the Holy Roman Emperor's coronation marks Viking culture becoming European.
As Truman comes to accept the secret Sylvia revealed, he tests the limits of what he can get away with and tries to escape Seahaven. Producers rush to explain the strange incidents to keep the truth hidden from Truman.
Alan Davies and Marcus du Sautoy visit the UK's National Physical Laboratory, where Mark Oxborrow takes them through an experiment that demonstrates how prime numbers exist in nature, and the Riemann hypothesis.
Microbiologist Professor Mark Turner breaks down the science behind pickling, the role of hurdle technology when preserving food and how the addition of acids, salts and sugars protect your pickles by increasing the hydrogen ions and making it difficult for microorganisms to grow. Whether you love the strong flavour of pickles or not, acids play an essential role in keeping your pickles bacteria free.
Professor Melissa Fitzgerald explains why starch thickens food, what time it is naturally produced in a plant and why that gives it such unique properties. From the onion-like semi-crystalline structure to its partial solubility, starch can undergo both glass transition and gelatinisation, making it a very interesting polymeric carbohydrate.
Ben Milbourne and Joel Gilmore use osmosis to cook up the perfect sautéed mushrooms, and Dr Arndrew Stephenson explains what exactly is happening when you use salt to accelerate the process. Osmosis is the transferal of liquids through a semi-permeable membrane. By adding salt, the water trapped within the mushroom's cell walls is drawn through the skin, or membrane, and into the pan as the two concentrations attempt to find a balance.
Bonita and Koiki's son accidentally ingests some kerosene and they must take him to the town hospital. After their son is released, the young family must find somewhere to sleep for the night, awaiting the morning train. All the hotels refuse to let the young indigenous family hire a room. After work the next day, Eddie takes a small stand against the endemic racism Indigenous people face.
Diggity accidentally ingests poison and begins to die. Robyn makes a difficult decision to put Diggity out of her pain. The loss of her companion sends Robyn into a spiral, and she struggles to continue. Fearing for Robyn's safety, Rick accidentally gives way her location and a troop of journalists descends upon her camp. That evening, Rick asks after Diggity and the next day Robyn breakdown, heartbroken and seeking companionship.