Mackenzie, Jack, and Rusty climb aboard the wooden boat, ready to blast off into a game of space adventure. They decide on their roles, with Rusty as captain, Jack as navigator or “dude-a-tron,” and Mackenzie as Chief Scientist, responsible for fixing things and figuring everything out. As they ponder their destination, Mars or a black hole, Mackenzie becomes fascinated with the mysterious black hole. Jack explains that a black hole is a hole that gets small, and what’s inside is unknown. Mackenzie takes a moment to think about this, possibly reflecting on a traumatic memory.
As they pretend to fly into space, Mackenzie interrupts the game, saying the ship has hit a meteor. Jack corrects him, saying it’s called an asteroid. When Mackenzie checks the “boosters,” Rusty asks if there are more asteroids around, and Jack replies that there aren’t. However, Mackenzie pretends to get hit by an asteroid and falls down the hill. Rusty jumps out to save him, only to find Mackenzie hiding behind a tree with a worried expression. After retrieving him, they continue their game, landing on Mars with Mackenzie still looking upset. Jack asks how the asteroid wasn’t detected, and Mackenzie says it must have damaged the dude-a-tron. When Jack questions how the tether came undone, Mackenzie ignores him and continues with the game.
As they prepare to take off again, Mackenzie quietly slips away, and Rusty notices. When they find him, Mackenzie claims they left him behind, but Rusty and Jack refute this. Jack realizes that Mackenzie unhooked his own tether, which Mackenzie reluctantly confirms. He wants to pretend he’s alone, but when asked why, he doesn’t know. Rusty and Jack tell him they need a Chief Scientist to get to Mars, so Mackenzie rejoins them. As they put the crew into hyper sleep, Mackenzie sabotages the game again, changing course to the black hole. When Rusty and Jack catch up, Mackenzie wants to enter the tunnel alone, saying it’s his duty as Chief Scientist. Rusty agrees, but as Mackenzie enters the tunnel, he unlocks a traumatic memory of being left behind at a playground. However, the memory takes a turn as Calypso finds him and reassures him that his mom is on the other side, and he just got mixed up in the slide. As the memory fades, Bluey, Indy, and Chloe, dressed as aliens, try to drag Mackenzie away, but Rusty rescues him. As they head back to the ship, Jack requests a crew check, and after a moment of hesitation, Mackenzie confirms he’s present and rejoins the group.
