This is a zero-spoiler post. For those of you planning to watch stage 10 later today, have nothing to fear. This is a picture of the elevation profile for stage 10 which takes the peloton from Saint-Gildas-des-Bois to Saint-Malo.
This is what one calls a sprint stage. It does hide the fun of the final 100m over cobblestones, the very point at which the sprinters accelerate in their battle for position. If you've never ridden over cobblestones, trust me, it can be brutal.