The itinerary lasts 14hrs 06min, and has 3 steps.

Nantes - Paris
The step from Nantes to Paris lasts 2hrs 07min. You'll travel in a high speed train.

Paris - Briançon
The step from Paris to Briançon lasts 11hrs 34min. You'll travel in a night train.

Briançon - Serre-Chevalier
The step from Briançon to Serre-Chevalier lasts 00hrs 25min. You'll travel in a day bus.