Recap
Dr. Zoidberg comes into some money when the Robot Mafia stashes the proceeds from an armed robbery in a dumpster that he's occupying. He decides to spend the money by gambling in Mars Vegas. He loses it all, but enjoys a taste of the life of the 1% for a short while. However, the Robot Mafia comes calling for the money, which he doesn't have. He uses his ink to escape, and winds up accidentally turning invisible thanks to being hit by Professor Farnsworth's tattoo-erasing laser.
The Robot Mafia, in order to recoup their ill-gotten loss, decide to take control of the Wong's casino and mansion, because they're the Robot Mafia and can boss people around. Amy decides to hatch a heist plot using the invisible Zoidberg to break into the casino vault when it opens, having him eat the money and a mysterious case inside. They almost get out scot-free, but are caught at the door by one of the native Martian security guards. Amy then reveals what was in the case: the original agreement that the Wongs had with the Martians, which grants the Martians the rights to the casino and all the land on Mars. They then decide to kick out the Robot Mafia from what is now their casino, and give the Wongs their mansion and other casino back.