The original concept of the series was that each episode took place in real time. A timer on the corner of the screen counted down from 22 minutes, pausing in the middle for one commercial break. The timer was discontinued after a few episodes. For the second season, the conceit was abandoned altogether in favor of a more conventional time structure, perhaps due to a combination of network pressure and the difficulties in planning and filming the action so that it appears to unfold in real time.