Stacking rigid cover

A method of operating a retractable cover system, the method comprising:

• providing a cover system including:
• laterally spaced apart guide rails defining an opening and each providing a track;
• a cover has multiple slats configured to interlock with one another in a deployed configuration, the slats cooperating with the drive assembly and slidable in the tracks between first and second positions within the opening in response to actuation of the drive assembly, wherein each of the slats include inner and outer surfaces, the slats stacked onto one another in a stowed configuration, wherein all of the outer surfaces face one direction, and all of the inner surface face another direction opposite the one direction, wherein the multiple slats includes first and second slats, the first slat above and adjacent to the second slat in the stowed configuration, the first slat in a horizontally overlapping orientation with the second slat in a first position, and the first slat in a horizontally planar and interlocked orientation with the second slat in a second position;
• a follower supporting the slats;
• and
• a spring-biased pulley system having a cable configured to cooperate with the follower and bias the slats toward the tracks;
• deploying the slats and decreasing a cable tension in the cable when the first and second slats transition from the first position to the second position;
• and
• stowing the slats increasing the cable tension when the first and second slats transition from the second position to the first position.