Concept Idea for an Opening Sequence 2

My second idea is a drama opening sequence where there is a professional assassin for the CIA as well as a double agent. It would be set in a room portraying the MI6 building with a predominantly female cast. I believe we could recreate a room in Hurtwood School portraying a room in the MI6 building with simple objects such as smart desks, chairs, paper, files etc. In this opening sequence we could use one room portraying an office like environment and another room with lots of computers portraying coding and data. The cast would most likely consist of about 4 people who would all play people who work in MI6 and the professional assassin. 

The professional assassin is assigned to kill a foreign agent. The foreign agent happens to be the professional assassin’s sister. The rest of the film narrative is going to be how the professional assassin discovers that her sister is still around and living a double life and how she is torn between work and love and the mental struggles she has with the task she has been given. However, she does eventually assassinate her sister regardless of their relationship.