Will and Nico got into a fight..

They're arguing about..well..you'll see.

Will: "I'M DONE! YOU SPEND TOO MUCH TIME IN THE UNDERWORLD AND WHENEVER I'M OVERWORKED AFTER DAYS OF HEALING IN THE INFIRMARY YOU'RE NEVER THERE! I'M SICK AND TIRED OF BEING IGNORED!"

Nico: "WELL IT'S NOT MY FAULT MY DAD CAN'T DO HIS JOB RIGHT, UNLIKE APOLLO! HADES DOESN'T EVEN KNOW WHO THE HELL I AM HALF THE TIME!"