The Carnival appeared during the second arc of World 1, and soon began trying to recruit new members under Samuel Sullivan's guidance and leadership. The individuals they tried to recruit included Keitaro Kiryuu, Sinead O'Brien, David Johnson and Shaleigh Johnson. The New Company tried to stop Samuel, but their first raid was unsuccessful, with agents Stephan Towley, David Johnson and Eoin Connell being captured and barely escaping. However, Samuel was ultimately stopped when he tried to publically reveal his ability by attacking New York. He was stopped by the previously mentioned agents, along with Sinead O'Brien, Sean O'Brien, Rooreru Kiryuu and Keitaro Kiryuu. Shortly afterwards, Sinead exposed abilities to the world by publically using her own ability.
In World 2 also, the Carnival first appeared as they tried to recruit others evolved humans including Jack Calwin, Joshua E Huston and Dani Millbrook. Dani joined temporarily, guided by her instincts which told her this was a task she had to do, until Samuel seemed to have killed Nathan while fighting with him. She then left. Luckily, Nathan had managed to mimic air and thus survived. The Carnival manipulated Joshua's memories, making him believe that he'd been born as a member and then abducted from them as a child. He also fell in love with Lydia there, and they were married, ending his prior relationship with Pippy. She too met her current husband, Gabriel Gray, at the Carnival. Joshua remained a loyal Carnival member until he learned the truth of how Joseph had died, and after that he covertly turned against Samuel since Joseph had been a mentor and father figure to him, in his new memories. He remained in the Carnival while working with the Organisation, Noah Bennet and Lauren Gilmore. Months later, Samuel began attacking towns with his power, and so Noah and Lauren made their move. However, it was unsuccessful, and Lydia was killed. They attacked again with the Organisation helping, and after Nathan persuaded all the other members of Carnival of Samuel's guilt by projecting the relevant memories, Joshua killed Samuel in order to avenge Joseph, Lydia and their unborn child. Lydia and the child were afterwards saved by Joshua, using advanced empathy, and Joshua and Lydia began leading the Carnival. They have been silent and lived mostly under the radar in the years since.
In World 3, the Carnival was discovered during the explosion timeline after Edgar was sent to kill a man going by the alias of Pavlove. James Herriford and Eve Kings investigated this, and it led them to learning of the Carnival, and Samuel's plans to attack New York. They planned to stop him. They were joined in this by Jack Calwin, who'd been recruited to do so by Lydia, and warned about Samuel. Together, they intercepted and negated his attack, and convinced all the other Carnival members to abandon him. He was then captured by the government. The Carnival is yet to make any appearance in the new timeline.
In World 8, the Carnival is still led by Joseph Sullivan, who remains alive in this world. He is however failing to bring in big crowds after evolved humans were exposed. People call them frauds and nothing is magic about The Carnival anymore.