Earth Double Prime is an almost exact duplicate of the Sliders' world of origin, Earth Prime. This Earth's Quinn Mallory, Wade Welles, and Rembrandt Brown went sliding just as the series protagonists did; the key difference is that Maximillian Arturo backed out at the last moment and did not accompany them.
Other differences are subtle (such as that the Niners played against the Jets in Super Bowl 19, whereas on Earth Prime, the Niners played against the Dolphins and Tom Kenfield, Quinn's ninth grade classmate, did not wear braces) and could only be noticed after a few days of carefully looking for them. The most obvious difference is that the Golden Gate Bridge is blue and is known as the Azure Gate Bridge.
When the Sliders arrived on Earth Double Prime, they at first thought they were home. Shortly thereafter Arturo became famous when he declared himself the true inventor of sliding. However, Quinn discovered the minor differences and tried to convince the others. They at first didn't believe him and thought that he might have been going insane. However, they realized that he was right when they saw the Azure Gate Bridge.
When trying to retrieve the Timer from Arturo's house, the Sliders discovered him or his double tied up in the basement, and also discovered that the Arturo that took credit for Quinn's invention was this world's Arturo. However, when they were about to leave, Arturo or his double showed up claiming to be the real one, explaining that he had escaped from the basement earlier that day and had captured the alternate Arturo.
The Arturo that the Sliders had freed knocked the other Arturo out and the Sliders went to Quinn's front lawn to wait for the sliding window to open. However, the other Arturo arrived in a cab and said that they were making a mistake and that he was the real Arturo. Quinn planned on taking them both through the portal and sort out who is who later. The Arturo that the Sliders had freed remarked "like hell we will", and attacked the other Arturo. During the fight, one of the Arturos punched the other and went through the portal with the Sliders.
After the portal had closed, the other Arturo stood up and remarked "Oh my god!", possibly indicating that the Arturo that slid with the Sliders was the wrong one. It is not known which Arturo went with the group.