A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

Tsar Alexander II (1818–1881) known as “The Liberator” lying in state. He was mortally wounded by an assassination attack in St Petersburg. (Photo by Hulton Archive/Getty Images). March 1881

Two guards perform an execution in China, one holding the gun, the other holding a mask over the victim's face. (Photo by General Photographic Agency/Getty Images). Circa 1925

Japan's computer giant Fujitsu employee displays the world's first personal computer with Intel's RealSense 3D camera “FMV Esprimo” in Tokyo on October 9, 2014. The new desktop PC with 23-inch LCD display can make avatars which mimic the user's look and motion for chatting on the Internet. (Photo by Yoshikazu Tsuno/AFP Photo)

Cardboard cut outs of the faces of three candidates for the Republican nomination for the 2016 US Presidential election (L-R) Ted Cruz, Donald Trump and Marco Rubio, are seen set up on urinals in a pub in London on March 1, 2016 as part of an informal poll for customers to log which they dislike the most. Part of the satirical television show The Last Leg, customers at the pub are able to choose which urinal to use and then log their poll on a list on the wall afterwards. (Photo by Justin Tallis/AFP Photo)

The civilised world lies on its knees, a sickness wracking its body. The affliction causes a necrotising of tissues so perfectly uniform in distribution that victims take on the appearance of corpses long before death occurs due to organ failure or secondary infections. ...

Athlets run during the women's 3000 meter steeplechase at the International Athletics Meeting in Lucerne, Switzerland, 14 June 2016. (Photo by Alexandra Wey/EPA)

In this Monday, July 25, 2016 photo, skydiver Luke Aikins smiles as he jumps from a helicopter during his training in Simi Valley, Calif. After months of training, this elite skydiver says he's ready to leave his chute in the plane when he bails out 25,000 feet above Simi Valley on Saturday. That's right, no parachute, no wingsuit and no fellow skydiver with an extra one to hand him in mid-air. (Photo by Jae C. Hong/AP Photo)