As a prosecutor, Robert Mueller took on violent Hells Angels, mob bosses and foreign spies. At the end of his career, he was tasked with hunting the biggest quarry of all: the president of the United States.
For two years, Mueller has been digging for the truth behind the most explosive political investigation in American history: did Donald Trump or his campaign conspire with the Russian government? And has the president been beholden to the Kremlin since his victory?