Overview
The Perks of Being a Jailbird is a small Blood and Wine secondary quest available only in Burlap is the New Stripe, when Geralt is imprisoned after Syanna’s death.
Walkthrough
After talking to Handsome Jacques in the yard of Toussaint Prison, check the wall that was behind Geralt during the conversation. A loose brick hides a note: another inmate needs a hammer and chisel. Both are in the wagon under the gallows. Put them in the hiding place behind the brick. A week later, as the guard leads Geralt to freedom, check the brick again to collect the reward.