A gambling barge run by the broker Haz Mazaro on the watery world Porathia, where Burnham and Booker competed for a supply of isolynium in 3190.
Haz Mazaro's Karma Barge is a casino and trading post moored on Porathia, seen in the Discovery episode All In. Its owner, Haz Mazaro, is an old acquaintance of both Michael Burnham and Cleveland Booker from their year as couriers, and he will sell anything to whoever pays most.
Book and Ruon Tarka come to buy isolynium, which Tarka needs for a weapon to destroy the Dark Matter Anomaly. Burnham and Joann Owosekun arrive to stop them. Owosekun raises a stake by winning bouts in the barge's fighting ring, and Book earns credit by unmasking a Changeling who has been cheating the house.
Mazaro settles the sale with a game of Leonian poker that also includes former Emerald Chain members. Book wins the isolynium, but Burnham has hidden a tracker on it.