Browse all 25 episodes in this season, including available images, air dates, runtimes, ratings and episode summaries from TMDB.
Episode 1
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Episode 2
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Episode 3
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Episode 4
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Episode 5
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Episode 8
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Episode 9
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Episode 10
An extremely rare genetic disease passed down through generations, fatal familial insomnia's (FFI) primary symptom is sleeplessness, but with a fatal twist: victims are dead within months. National Geographic delves into the science of sleep to find out why we need sleep and what happens to us when we don't get it. Witness the pioneering research inside the sleeping brain as well as the mind forbidden to rest for days at a time.
Episode 11
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Episode 12
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Episode 13
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Episode 14
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Episode 15
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Episode 16
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Episode 17
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Episode 18
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Episode 19
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Episode 20
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Episode 21
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Episode 22
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Episode 23
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Episode 24
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Episode 25
Leonardo da Vinci's "The Battle of Anghiari" vanished 500 years ago, with only copies rendered by other artists left behind to confirm its existence. Scientist and art enthusiast Maurizio Seracini, has dedicated 36 years to tracking down the missing mural, and seems to be on the verge of uncovering the hidden fresco behind the walls of the Palazzo Vecchio in Florence, Italy.
Episode 26
TMDB has not published a written overview for this episode yet.
Episode 27
National Geographic writer Neil Shea travels to the heart of Kurdistan on a quest to meet the Kurdish fighters on the front lines against the world's biggest terrorist threat, ISIS.