The Callistos arrive at the gas giant Neptune for Miles' Cosmic Explorers field trip to the Trident Research Station. Even Loretta is coming along because she's a huge fan of Professor Rubicon, the smartest astrophysicist in the galaxy and will be leading the tour on the research station. They soon arrive at the Trident Research Station and after Phoebe and Leo drop off Miles, M.E.R.C. and Loretta, they meet up with Professor Rubicon himself and the other members of Cosmic Explorers, Blodger and Pipp. Loretta becomes so delighted to meet Professor Rudicon in person that she forgets her own name.
The tour of the Trident begins with a presentation about what makes Neptune so grand, being larger than fifty-seven Earths combined and a new frontier. While floating around without the artificial gravity, Miles asks Professor Rubicon about how can Neptune be a new frontier since ships have been passing this planet for years. He explains that a frontier isn't always some place far away, it can be anything that is unknown and Miles loves exploring the unknown. The tour later moves onto seeing a large model of Earth's solar system. Professor Rubicon tells the kids that Neptune is the coldest planet in the solar system, but not as cold as Triton, the largest of the planet's fourteen moons. The tour then moves onto to the control room where four operators are monitoring Neptune's weather conditions and maneuvering the Trident away from any nearby storms. Then finally the tour moves onto observation deck where they can see a lot of ice floating under them. While explaining that sometimes Neptune is refereed as an Ice Giant rather than a Gas Giant, the Trident is suddenly struck by a powerful storm, causing damage to one of the station's stabilizers. After the authorisation for all personnel to make their way to the escape pods, Professor Rubicon escorts the kids to the nearest one when suddenly passing ice breaks off the damaged stabilizer causing the whole station to lean to one side, accidentally launching Professor Rubicon off the station without the kids.
With all the escape pods launched, the kids remain trapped on the station. Professor Rubicon makes contact with them and tells them he has sent word to their families and are now on there way to get them. He also tells them they will have to return to the docking bay in order to meet up with them, but since the Trident is now on its side the docking bay is now at the top of the station. After losing contact with Professor Rubicon, the kids are now on their own in finding a way to get back to the docking bay. With M.E.R.C.'s help and Miles' Blastboard, they manage to fly up to other side of the observation deck and make it to the hallway, which is flooded with water due to broken pipelines. With Pipp's help, he manages to drain out the water by opening one of the doors. The kids make it back to the control room which is now filled with collapsed scaffolding. Knowing they cannot fly through it they decide to climb it instead and soon reach the model room where they find all to model planets bouncing around like crazy, due to the computer that controls them being damaged. They climb through the bouncing planets and nearly get rolled over by the model of Neptune but make it safely back to the docking bay. However, nobody has arrived yet and worse is yet to come when the kids discover the Trident's haul is beginning to crack which will no doubt burst open and everything inside will be sucked outside, including them. Miles tries to contact his parents but can't reach them due to some interference.
Meanwhile Phoebe and Leo arrive back at Neptune to rescue the kids and arrive just in time as the Trident's haul continue to break. Using Miles' Lazerang to hit the gravity button, the kids push off and float through the airlock and arrive safely aboard the Stellosphere, moments before the haul collapses completely. The Kids are soon reunited with their parents and Professor Rubicon rewards the Cosmic Explorers with their Neptune Holo, including Loretta, making her an honorary Cosmic Explorer. Voted by the others to give one member an additional award, Professor Rubicon rewards Miles with the Cosmic Explorer Leadership Holo for exhibiting courage and resourcefulness while leading the way to a new frontier.
- Cullen McCarthy as Miles Callisto
- Fiona Bishop as Loretta Callisto
- Olivia Munn as Phoebe Callisto
- Tom Kenny as Leo Callisto
- Dee Bradley Baker as M.E.R.C.
- Eathen Wacker as Pipp Wimpley
- Bill Nye as Professor Rubicon
- Grey DeLisle as The Trident's Computer
- Sam Lavagnind as Blodger Blopp
- The crest on Professor Rubicon's uniform is a trident, which resembles the astronomical symbol of the real Planet Neptune.
- The Trident Research Station is named after the spear held by Neptune, the goddess of water from Roman mythology, whose name is also of the Planet.
- The Cosmic Explorers make their second appearance in this episode, followed by "Explorer Exchange".