The present paper titled 'Dementation' in Shashi Deshpande's Ships That Pass speaks about Tara, a married woman who is psychologically disturbed by the disloyalty of her spouse. Women are highly sensitive by nature and are easily affected by the problems they face in their marital life. A person becomes mentally depressed when he/she is deprived of emotional, social or monitorial help. This state of mind when left uncured causes insanity, which is extremely stigmatized in our society. The novel explores the reality of women's inability to cope with the pressure of patriarchy. Shashi Deshpande who is an expert in dealing with the mystery of human mind has dealt with the same formula in her latest novel Ships That Pass. The novel is a suspense thriller which revolves around a couple who conceal them selves in hush. Keywords: marriage, disloyalty, patriarchy, insanity, mystery etc.