A retractable cover system includes laterally spaced apart guide rails that each provide a track on either side of an opening. The retractable cover system further includes a cover that has multiple slats that are configured to interlock with one another in a deployed configuration. The slats are slidable in the tracks between first and second positions within the opening. The slats are stacked onto one another in a stowed configuration. The slats include laterally extending profiles that are complementary to one another and are configured to interlock with one another in a deployed configuration. The complementary profiles are configured to decouple from one another in the stowed configuration.