The best explanation of the XYZ affair during John Adams' presidency is:
Adams tried to promote peace with France after French pirates started seizing American ships, but three French officials (X, Y, and Z) demanded a two hundred- and fifty-thousand-dollar bribe before they would even speak with Americans.
This incident, which occurred in the late 1790s, involved American diplomats being sent to France to negotiate peace due to increased tensions and attacks on American shipping. The French officials, referred to as X, Y, and Z, demanded bribes and loans as a prerequisite for negotiations, leading to public outrage in the United States and ultimately contributing to an undeclared naval war between the U.S. and France known as the Quasi-War.