Ursula and Sabina Eriksson are identical twin sisters born in 1967 in Sweden. They seemed to live a normal life, with no criminal history or mental background, until May 17, 2008. Ursula and Sabina secretly left Sabinas home and took a ferry to Liverpool. After a chain of bizarre events, Ursula was left hospitalized with 2 broken legs and Sabina was put on trial for murder. What made these seemingly normal twins flip?