Individuals Scheduled to Appear in Congress to address matters related to the Trump-Russia investigation and allegations of a conspiracy:

Bill Barr, former Attorney General, Department of Justice
Alberto Gonzales, former Attorney General, Department of Justice
Jeff Sessions, former Attorney General, Department of Justice
Robert Mueller, former FBI Director, Federal Bureau of Investigation
Loretta Lynch, former Attorney General, Department of Justice
Eric Holder, former Attorney General, Department of Justice
Merrick Garland, Attorney General, Department of Justice
James Comey, former FBI Director, Federal Bureau of Investigation
Bill Clinton, former President of the United States

Hillary Clinton, former Secretary of State, Department of State