It's raining and people are running for shelter. The threshold at the top of the stairs indicates a transition from one reality to another. Perhaps from this temporary reality to the eternal afterlife. Or perhaps we could see it as Dante's Mount Purgatory. Some people seem to be stumbling over what appears to be a third leg, while others seem to be sailing swiftly along. Or are they, on closer inspection, slipping on the wet surface? And some have made it, as it were, they have completed their trials and are being let in.