The Circus Dimension is a parallel dimension of unrevealed designation that the Hungry Manitou escaped to.
The Hungry Manitou was one of the ghosts accidentally released from the Containment Unit when Ron Alexander and Jillian Holtzmann tested their Remote Access Teleportation Unit. A few days later, a field team consisting of Ray Stantz of Dimension 68-R, Gabriel Sitter of 50-S, Janine Melnitz, Ron Alexander, Patty Tolan of 80-C, and Garrett Miller of 68-E arrived in search of it. They canvassed a circus. Garrett was possessed by the Manitou and it generated a Giant Murder Clown construct around themselves for protection while it fed. Despite Janine's objection, Ron employed a Proton Grenade. The Murder Clown retaliated and fired deadly projectiles that resembled ice cream cones. Patty tackled Ron out of harm's way. Ray 68-R and Gabriel wondered why he wasn't fired yet. Janine stated they wanted him where they could keep an eye on him and were waiting for memory erasing technology to be perfected by Egon. Ron quipped they didn't want him selling everything he knew to the highest bidder. Ron was stopped mid-sentence and realized three of the Murder Clown's projectiles had pierced his chest and stomach then he fell to the ground.
The remaining Ghostbusters opened fire on the Murder Clown while Ron threatened to sue. Patty proposed using the Trap-Gates to exorcise Garrett but Ray 68-R countered they then wouldn't have any left to send the Manitou to the Containment Unit. He believed their only move was to weaken the construct with full power streams. Garrett found himself on the mental plane and met the Hungry Manitou. The Manitou called him greedy and dumb, took his form, and grabbed him. It was confident Garrett wasn't nowhere near as smart as Peter Venkman. Garrett surprised the Manitou and broke free then fought back by imagining his feet into particle throwers. The Manitou called him an insecure fool that pretended to take pride in being half a man as it created three zombie-like constructs of Eduardo Rivera, Kylie Griffin, and Roland Jackson that tried to mess with his mind. Garrett recognized those as thoughts he had on his bad days. He countered he didn't have many of them and conjured a proton slinging wheelchair then blasted the Manitou at full force.
Patty realized their attack wasn't enough against the Giant Murder Clown. Ray 68-R thought they stood a chance when Garrett fought back against the Manitou and its readings went into flux. Janine knew they needed something else. Ron came to and told Gabriel to cut his Proton Pack off and call the "fat guy" over. Gabriel assumed he was talking about Ray 68-R. At first, he didn't get it but Ron explained the Proton Grenade stunned it but blowing up the Proton Pack would be strong enough to free Garrett. Ray 68-R agreed and congratulated him for saving Garrett's life. Ron could care less, he needed a doctor fast. Ray 68-R threw the pack into the air and ordered everyone to shoot it. The explosion dispersed the Giant Murder Clown and freed Garrett. The Manitou was angered. It decided to forgo its hunger and kill everyone. Garrett blasted its back as it charged towards the others. Gabriel threw out his Trap-Gate and captured the Manitou. Janine checked on Garrett but got annoyed when he continued to refer to her as "ma'am" even after she said it made her feel old. She reckoned they should find Garrett's wheelchair and probably take Ron to a hospital. Before Ron could react, Patty warned they would leave him stranded if he said another word. Gabriel thought they did relatively well, having only used two Traps. Janine declared it was such a disaster and remembered why she hated going out into the field. Ray 68-R was surprised and revealed his dimension's Janine loved to bust ghosts. Janine reckoned she didn't have much common sense. They opened a portal home but only Ron returned to the prime dimension. The others were redirected by Tiamat to the Collectors' Limbo.
- On page 18 of Ghostbusters Crossing Over Issue #5, in panel 4, on the white popcorn bag is Cheap Thrills Amusement Park and its clown face from The Real Ghostbusters episode "Rollerghoster".
- On page 8 of Ghostbusters Crossing Over Issue #7, in panel 3, on the rear of one of the caravans is Luis Antonio Delgado's 15 easter egg.