We Alexander is based on the story of the third son of King William III and Sophie of Württemberg. According to the history books, this Alexander had a short life: from 1851 to 1884. The amazement of psychiatry student Jan Giltay is therefore great when, in 1909, he meets a certain patient number 4 in a clinic who claims to be Prince Alexander. Indeed, the man knows a remarkable amount about life at Court. There are also increasing indications from other quarters that this could very well be the 'forgotten' crown prince. Moreover, patient number 4 is said to have a mysterious box - with information that could shake the entire royal family to its foundations.