 Nothing succeeds like success. And there has been no greater success than the CBI Diary Kurippu series. And there has been no better successful investigator than Sethurama Iyer in the history of Malayalam cinema.
So, in a sense, Nerariyan CBI (a historical fourth in the series) has success built into it. And all that director Madhu had to do is play his cards shrewdly without being over ambitious. And he does precisely that and the rest is taken care by the essential polish, poise and panache of Mammooty. The man looks a CBI investigator, manner born.The series could not have been possible but for his admirable tall presence. The overall plot --- of the never-say-die inspector cracking a seemingly closed case --- may be predictable. But like the Tom and Jerry exchanges, the sub-plots are interesting.
The story unfolds in the rambling mansion of Animngalam Tharavad, tucked inside the cavernous labyrinth of which are dark secrets and darker intents (of some individuals).
 When Anitha (Gopika), comes with her friends to Tharavad, things become decidedly sinister. One girl is killed and the cops close the case as a case of outre happening.
But Sai(Jishnu), the suitor of Anitha, is not convinced. On a chance meeting with Sethurama Iyer several years later, Sai tells him his suspicions.The rest, as they say, is his story ---Seethurama Iyer's, that is. He unravels the jigsaw and pieces them together with the help of his old lieutenants Chacko and Hari (Mukesh and Jagathy). The climax is indeed interesting and engrossing.
Mammooty walks away with all the honors. It is almost impossible to conceive anybody else in the role. He doesn't complicate things and keeps his acting nice and straight. His run-ins with Kapra (Thilakan), the local Tantrik, are indeed sparkling.
Gopika looks cute, but has nothing much to do. Jishnu too has a miniscule role. But every one of them goes through his or her routine with conviction.
Shyam's music is sturdy and situational.Salu George's camera work is classy and neat.
Madhu has very little to do as a director. All he has done is just the whirred the camera on and then let Sethurama Iyer take over.
| 
- 
