The film begins with blatant cheating in the examination hall. Somnath (Pradip Mukherjee), an honest student, finds himself doing badly in the exams due to an overworked examiner, without his glasses who is unable to read his small handwriting. As he is in no position to marry, his girlfriend gets married to someone else due to pressure from her family.

A bright and idealistic young man, Somnath begins search of a job along with his more realistic friend Sukumar (Gautam Chakravarti). With the job market flooded with thousands of hopefuls, Somnath faces some absurd interviews. He gives up his search after an interview in which he asked, 'what is the weight of the moon?' Later, he encounters an older man, the street-smart businessman, Bisuda (Utpal Dutta). On Bisuda's advise, Somnath becomes a middleman, an order supplier paid on commission. His father, an upright middle-class man considers this business to be disgraceful to the family reputation.

Somnath, soon, finds himself earning through petty deals but he is ambitious and wants to grow his enterprise. His friend Sukumar, however, has not had much luck and now works as a taxi driver.

There is chance of Somnath landing up with a big order but the client seems to be in no hurry to sign the deal. An acquaintance, Mr. Mitter, advises him to supply the client with a prostitute to clinch the deal. After much hesitation, he agrees.

They go in search of a prostitute. After visiting two brothels, they finally find a girl. She turns out to be his friend Sukumar's sister. Somnath asks her to take the money and leave, but she is a professional and would not take money with out earning it. Somnath agrees and delivers her to his client's room in a hotel.

He gets the contract but it does not bring him any happiness. Finally, as he enters his family house through a dark door, he is no longer an innocent boy but a corrupt man who has discovered the advantages of corruption.

This is the final film of trilogy known as the Calcutta Trilogy. The first two were Pratidwandi (The Adversary, 1970) and Seemabaddha (Company Limited, 1971). All the three films study the effect the big city of Calcutta has on the educated youth and the price it extracts from them.

Ray told in an interview to Cineaste that the only bleak film he had made was The Middleman. The film is about corruption of a young man; from an idealistic individual to a corrupt businessman who ends up offering his best friend's sister to a client for a business favor.

Superb performances by all the leading actors.

... few of Ray's films have offered so wide a range of quick, exact characterizations.
- Penelope Houston