A stranger with torn clothes and a bloody face staggers into Heber Finn's pub to report a collision on the road. Collisions, however, are familiar occurrences here for the customers at the pub all know exactly what to do when they hear word of a wreck. That is, everyone knows except an American named McGuire. He heard no car on the road and, furthermore, heard no sound of collision. He sits mystified. McGuire soon learns that the accident involved bicycles, not cars, and that it took place at the crossroads, in the fog, between two bicycles devoid of lights. He also learns that over three hundred Irish bicyclists have similar collisions each year. When he questions the doctor about whether or not automobile collisions ever occur, the doctor tells him to go to Dublin if his interests concern auto crashes. He gives McGuire further information: "When there is a heavy fog, speed, and douse your lights when cars loom up." With these instructions, McGuire looks at the highway boiling with fog and, with high anticipation, he starts his car.
Another of Bradbury's nationalistically oriented stories, "The Great Collision of Monday Last" treats several of humanity's blacker desires. Here, he depicts the thrill which a person feels when he flirts with danger and the unknown, and when, more specifically, he readies himself for the possibility of destroying a life. McGuire may be an American, but the thrill associated with danger and destruction serves to break down all nationalistic barriers because it is common to all people. In this respect, McGuire and the men at Heber Finn's pub are brothers.