After its surprise result in the Assembly by-poll in West Bengal on Thursday, where it came second, top BJP leaders flew into to Kolkata on Friday with one war cry: agli baar BJP sarkar in Pashchimi Bangal. Mamata Banerjee's Trinamool Congress has laughed it off. A leader said "even mad men would laugh at such a claim". But privately, Kanthi South result has set alarm bells ringing for the Trinamool, Left and the Congress.