Marion's Triumph is a special kind of celebration where someone named Marion won a big and important race. It's like when you play a game with your friends and you win, except this is a really big and important game! People are really happy and proud of Marion for working hard and doing their best to win the race. Everyone claps and cheers for Marion and they maybe even get a special medal or trophy to remember their big win! It's a really happy and exciting time for everyone involved!