premise: The principal cemetery of Montmartre, where luminaries of the arts such as the composers Berlioz and Offenbach lie buried, may seem a world away, but it's only a short walk west from the Moulin Rouge to the entrance (west past the Moulin Rouge, then right at avenue Rachel).
hypothesis: When it rains, the walk from the Moulin Rouge and Montmartre is slippery and dangerous.