Film synopsis- what our film is about

The film opens with a scene where a pair of twins (one boy, one girl) are cutting their 5th birthday cake as they celebrate their big cake. The brother is called Lucas, and the girl is Alex. No one knows this yet, but Lucas has been born with a severe case of multiple personality disorder, which can later be mistaken for schizophrenia. A few days later, as Lucas and Alex play in the woods… Lucas then goes mysteriously missing. As Alex screams for Lucas, he is nowhere to be seen. He unknowingly goes missing, thinking nobody cares about him. Thirteen years later, Lucas is back. Only to haunt his twin sister Alex, on none other than their 18th birthday. Lucas’s illness gets the better of him, as he tries to kill his own sister due to his multiple personality disorder. He thinks that she does not love or care for him, and he’s back for revenge this time. Despite his constant effort to kill Alex, he is unsuccessful. Alex survives, having killed her own brother in self defence. Alex is the final girl in the film, and follows the ‘final girl theory’ by Carol Clover.