在一个颇有些阴郁的日子里,威廉姆斯医生(马丁·弗瑞曼 Martin Freeman 饰)接到通知来到某座监狱。面无表情的监狱长接待了他,他向威廉姆斯介绍了狱中一个奇怪的病人乌尔曼先生(汤姆·霍兰德 Tom Hollander 饰)。乌尔曼自称是神,监狱长希望威廉姆斯医生能帮忙对乌尔曼进行鉴定,一旦确定对方患有精神病就可以将其转入精神病院。由于上一年监狱方的电脑崩溃,所以医生和监狱长都无法确认乌尔曼当初是因为什么进了监狱。在没有任何可以参考的文献帮助下,威廉姆斯只能硬着头皮走进牢房,和神秘的乌尔曼面对面交谈……Doctor Williams is called in to examine the enigmatic Mr Voorman, a prisoner with a peculiar affliction: he believes he is a god. The Doctor must decide on the sanity of Mr Voorman - is he a faker or a lunatic? Diagnose him insane and they can ship him off to the asylum. But before making a decision, the Doctor has several questions in relation to Voorman's claims: why would a god choose to be straitjacketed in a prison, is there a way he can validate his boast and what has any of this got to do with Belgium?