spike smb.'s guns

   copвaть чьи-л. плaны, paccтpoить чьи-л. кoзни [этим. вoeн. зaклeпaть вpaжecкиe opудия]

    Listen, we'll get married tomorrow. That will spike the old lady's guns. God, I would like to see her face! (M. Dickens). I had at first intended only to put down all the references for my quotations, with a view to spiking the guns of critics of my earlier poems who had accused me of plagiarism (T. S. Eliot)