Later on, Jarre tried to join the Mahakam Volunteer Army but was ultimately assigned to the Poor Fucking Infantry, together with his childhood "friend" Melfi. The PFI, under the voivode Bronibor, took part in the Battle of Brenna and was charged with stalling Nilfgaardian advance until reinforcements arrived. Consisting of commoner pikemen with little to no combat experience and matched against the enemy's heavy cavalry, the PFI sustains heavy casualties and Jarre lost his left hand in the battle. Despite their lack of experience, the unit successfully halted the enemy.
Some time after the war, Jarre settled down and married a woman named Lucienne and wrote a book called "Annales seu Cronicae Incliti Regni Temeriae" (which roughly translates to "Annals or Chronicles Celebrating Temerian Rule"). It's known that his granddaughter's name is Ciri.