Plot synopsis: Mathilukal ('Walls') is a free adaptation of the novelette of the same name, written by the celebrated Malayalam writer, Vaikom Muhammad Basheer. Autobiographical in character, it is set against the background of India’s freedom struggle in the ’40s when he was serving a term of imprisonment in the Trivandrum Central Jail. When the film opens, we see Basheer in a police lock-up, quite at home in the company of a few petty criminals. He has been languishing there for more than a year now without a trial.