Abby then showed them the lines from the Marine’s main chute. They had been weakened by some sort of acid and then the lines shredded when he jumped out of the plane. With Abby’s usual assistant out for the day, Gibbs tapped Caitlin to stay back to assist her while Gibbs and Tony left to question the Marine’s team again, specifically Corporal Dafelmair, one of the riggers who was in the same team as the dead Marine.