Four times during the first six days they were assembled and briefed and then...

Four times during the first six days they were assembled and briefed and then sent back. Once, they took off and were flying in formation when the control tower summoned them down. The more it rained, the worse they suffered. The worse they suffered, the more they prayed that it would continue raining. All through the night, men looked at the sky and were saddened by the stars. All through the day, they looked at the bomb line on the big, wobbling easel map of Italy that blew over in the wind and was dragged in under the awning of the intelligence tent every time the rain began. The bomb line was a scarlet band of narrow satin ribbon that delineated the forward most position of the Allied ground forces in every sector of the Italian mainland.
For hours they stared relentlessly at the scarlet ribbon on the map and hated it because it would not move up high enough to encompass the city.
When night fell, they congregated in the darkness with flashlights, continuing their macabre vigil at the bomb line in brooding entreaty as though hoping to move the ribbon up by the collective weight of their sullen prayers. "I really can't believe it," Clevinger exclaimed to Yossarian in a voice rising and falling in protest and wonder. "It's a complete reversion to primitive superstition. They're confusing cause and effect. It makes as much sense as knocking on wood or crossing your fingers. They really believe that we wouldn't have to fly that mission tomorrow if someone would only tiptoe up to the map in the middle of the night and move the bomb line over Bologna. Can you imagine? You and I must be the only rational ones left."
In the middle of the night Yossarian knocked on wood, crossed his fingers, and tiptoed out of his tent to move the bomb line up over Bologna.