The main aim of this paper is to prove that the modifications made to Caroline Graham’s novel during the process of adaptation contributed to the success of this certain episode and later the series. The following chapter of the thesis contains some thoughts regarding adaptation. After defining what an adaptation is and what its most important components are, the types of adaptations according to four different categorizations will be displayed. Adaptation as a process is going to be analyzed in the next part of the chapter. Finally the differences between novels and films are going to be discussed and a special attention will be paid to the most significant factor of adaptation: economy. Chapters 3 and 4 contain an analysis of the mid-adaptation modifications and the new elements of the film. These chapters explore the changes and improvements made to the original work and analyze them in order to prove their raison d’être. Chapter 5 examines the elements that had to be left out of the episode with a detailed analysis of the reasons for omission. Finally I draw the conclusions and identify the type of adaptation the film belongs to.