A remake of the Malayalam film Cocktail (which, in turn, was an unacknowledged lift of the Pierce Brosnan-Gerard Butler-starrer Butterfly On A Wheel), Athithi is about a couple, Mathiazhagan ( Nandaa) and Vasuki ( Ananya), whose life is turned upside down in a single day when a stranger ( Nikesh Ram, somewhat wooden) comes into their life. This guy tells them that he has their daughter and orders them to do the strangest of tasks if they want to see their daughter alive.
This is a solid line for an edge-of-the-seat thriller (think Aamir, but with a foe who is very much visible and present nearby) but Bharathan, who directed Azhagiya Tamizh Magan earlier, resorts to formulaic filmmaking — unwarranted songs and a comedy track featuring Thambi Ramaiah that kills tension like bucketfuls of water dousing a minor fire; there is even a 'thaali sentiment' scene (the Malayalam film did not have one). The whiplash editing tries to whip up some tension but it only feels desperate and overdone.
And the needless epilogue only makes the film needlessly sexist. It punishes the woman who has transgressed while letting go of the man lightly.
And, yet, the in-built mystery in the plot (who is the stranger, what does he want and why is he tormenting the couple and of course, how does it all end) somehow keeps us hooked and the film deserves some praise for the manner in which it makes us, the audience, shift our sympathies from the hunted to the hunter. But only just that little bit. Not more not less.