Prigueux - How do you beat Marcel Kittel in a sprint?
That's going to be the question on the lips of every sprinter at the Tour de France on Tuesday.
After a gruelling mountain stage, Monday's rest day was welcomed by all and sundry and with two flat stages ahead before the Pyrenees loom, the sprinters will be licking their lips at the prospect of coming to the fore once again.
But these two stages won't be as straight-forward as the previous flat stages during the first week of the Tour, where small breakaway groups set off on doomed escapades as the sprinters' teams coldly and easily controlled their gaps.
Everyone is tired at this point in the Tour and no-one will be relishing leading the peloton, meaning there are rewards to be had for a determined group of escapees with a bit of energy to burn.
The peloton will more likely play with fire, give the breakaway extra leeway and take longer to launch it's final chase.
The sprinters, and their teams, are not only tired, but there are fewer of them now.
French champion Arnaud Demare missed the cut-off point on Sunday's brutal mountain stage and is out of the race.
Mark Cavendish and Peter Sagan had already left the race so that's three less teams likely to be interested in chasing down a breakaway, putting more onus on Kittel's Quick-Step outfit as he chases a fourth stage success.
At the same time, it is a day in which the overall contenders will be hoping for a minimum of drama, and preferably a leisurely pace.
Anything to rest the legs ahead of the Pyrenees, and then next week the Alps.
Many are nursing bumps, bruises and cuts from the numerous falls that affected the race on Sunday.
Two-time former champion Alberto Contador is one of those. He crashed twice on Sunday and lost more than four minutes to race leader Chris Froome.
He's now had to rethink his approach to the race.
"Most of you know me and know that I am quite optimistic, but now the priority is to recover and, if I do it, try to do the best I can," Contador told journalists on Monday.
"If so, my approach to the race will be completely different."
With Froome and his Sky team doing what they do best, controlling the race and stretching out his lead bit by bit every time there's a tough stage as one or more rivals lose time, everyone is going to have to think outside the box and try something different.
And maybe they will gain inspiration from Tuesday's 178km 10th stage which begins in the medieval town of Perigueux, a World Heritage site and important stop off point on the famous Camino de Santiago pilgrimage route.