Rivets was the head of Stable 99's maintenance, a strong-headed mare, and instigator of the insurrection against the Overmare. Frequented card games in the stable's lower levels and regularly made class B violations in the form of cigar smoking. Blackjack never reported her on it and the manufacturing of them remained a mystery.
After Deus' attack on Stable 99, Rivets led a portion of the population into hiding in the maintenance levels while the Raider Disease-ridden corpses were put through the Stables' recycler and infected the ponies on the upper levels. After Blackjack returned (in chapter 22) and put down those with the disease, Rivets and the other survivors were free to reoccupy the Stable, however they too ignored Blackjacks' warnings about the Raider Disease-infected corpses and put them also into the recycler and as such succumbed to the engineered virus. Rivets was already experiencing the first stages of the disease by the time Blackjack resolved to locking herself inside of the Stable and gassing it as a form of atonement and suicide after enduring so much pain and misery in her journey. Rivets was the second-to-last pony to see her killer before Lacunæ rescue-teleported the Security Mare outside.
