STACKING RIGID COVER

A retractable cover system includes laterally spaced apart guide rails that define an opening and each provide a track. The system further includes a cover that has multiple slats that are configured to interlock with one another in a deployed configuration. The slats cooperate with the drive assembly and are slidable in the tracks between first and second positions within the opening in response to actuation of the drive assembly. The slats are stacked onto one another in a stowed configuration. The system further includes a follower that supports the slats. The system further includes a spring-biased pulley system that is configured to cooperate with the follower and biases the slats toward the tracks.