The idea here is to drive the sword into the bull's heart. The picador's pike opens up the thick skin and muscle, but if the matador doesn't plunge the sword in accurately and hard, the bull won't die right away. Sometimes the bull wanders about for a few seconds with the sword in him, slicing up his insides. If the sword-work is done right, however, the bull goes down instantly in a big heap and is carted off.

You don't want to know what happens if the sword doesn't kill the bull after 30 seconds or so. You really really don't.