Wide Is the Gate, written in 1943, is the fourth of the epic eleven-part classic Lanny Budd series written by Upton Sinclair.

Wide Is the Gate followed the 1943 Pulitzer Prize–winning Dragon's Teeth and introduces Lanny as a secret double agent fighting the Nazis as a supporter of the resistance in Germany. Lanny is living in England with his wife of almost five years, Irma Barnes, the twenty-three-million-dollar heiress. But Lanny is conflicted continuously in his heart and soul for the workers and social justice. He attempts to commit to Irma, to "behave" himself and lead a normal aristocratic life. But foremost he is committed to ending Nazism, Fascism, and the overthrow of the democratically elected Spanish government.

Lanny is awakened at the end of Dragon's Teeth to the oncoming dangers of the Nazis, and involves himself in a double agent role by helping a new friend, Monck. Monck is a German socialist who is part of the underground and works with the resistance to alert people to the terrors of the Nazis.

Many adventures and dangers present themselves as Lanny travels back into Germany as an art expert, eventually dealing directly with Hermann Göring. He uses the proceeds of the confiscated artwork stolen by Göring to help finance the resistance from inside the heart of Naziland.