Mammooty returns to the role of the brainy CBI officer Sethuramayyar in Sethuramayyar CBI, the third installment in the series. The MO remains the same as the first two movies (Oru CBI Diary Kurippu and Jagratha) as he investigates a crime and wades through a sea of clues and suspects to solve it. It has too many unnecessary elements that affect the pace and has a few too many characters but still manages to be an interesting whodunnit.
Sethuramayyar(Mammootty), who now works in Delhi, is vacationing in his sister's house in Kerala when he learns that Alex('Kalabhavan' Mani'), a murderer who is on death row for killing seven people, wants to meet him. Alex accepts killing six of the victims but says that he did not kill the seventh one. Sethuramayyar, with Chacko(Mukesh) and a new assistant in tow, begins investigating to find out if Alex is telling the truth and if he is, who the real killer is.
Sethuramayyar CBI naturally sticks to the same story arc that worked the first two times. We get a large number of possible suspects with different links to the victim. There is one key element of the case that captures our interest(here its the word ISOW scribbled on the wall) and is eventually figured out by Mammootty. And the identity of the killer, revealed by Mammootty in a final monologue with all the suspects rounded up, is a nice surprise. So is the reference to an earlier throwaway comment by the killer that leads to suspicion falling on him.
In order to throw suspicion around, the movie has included too many characters and subplots. Due to nature of some of the characters, they are immediately evident as red herrings and so seem redundant. There are also one too many references to the first installment as we meet characters from that movie, get references to the investigating techniques used there and even hear one of the most popular lines from that film again. The movie also lays the foundation for a romance between Mammootty's niece and his new assistant but the casual way it is handled makes it seem more like filler.
Though it fails to match up to the quality of Oru CBI Diary Kurippu, Sethuramayyar CBI manages to keep Sethuramayyar's reputation intact. So we can look forward to the fourth installment, shooting for which has just gotten under way.