This subgenre is generally, as the name says, a film which is presented withour colours, so black and white. Classic film noir were developed during and after World War II, taking advantage of the post-war ambience of anxiety, pessimism, and suspicion. It was a style of black and white American films that first evolved in the 1940s, became prominent in the post-war era, and lasted in a classic "Golden Age" period until about 1960. Very often, a film noir story was developed around a cynical, hard-hearted, disillusioned male character who encountered a beautiful but promiscuous, amoral, double-dealing and seductive femme fatale. She would use her feminine wiles and come-hither sexuality to manipulate him into becoming the fall guy - often following a murder.
Medical Thriller This is a thriller, which is based on medical treatments and because it is a thriller, it is even more based on medical problems or mutations. The characters are trying to solve these problems, but while they are doing this, they also always get involved into the problem. This subgenre is more based on literature than on the film media.
Here are examples of authors of medical thriller books:
Romantic Thriller This thriller is a kind of mixture of a Romance Film with a Thriller. So on one hand you have the romantic site, which means that there might be like a lovestory or another romantic plot. This is then mixed with the thriller site, which adds the supsense and the real action to the film. These films are actually very hard to produce due to these two different categories.
