What happened behind the scenes between midnight and 5 in the morning on Sept. 9? That five-hour window could hold key details about President Donald Trump’s efforts to pressure Ukraine to investigate Vice President Joe Biden and his son. Gordon Sondland, the U.S. ambassador to the European Union who is set to testify before Congress in a secure room in the Capitol Basement Thursday morning, is one of the few people who knows what transpired during those early morning hours. After Bill Taylor, the acting Ambassador to Ukraine, texted Sondland around midnight on Sept.