S1·E46 Revenge of the Raenoks

When Booster is kidnapped by the Raenoks, in order to conduct a prisoner trade for Varg (XR is sent to guard Varg, who quickly escapes and takes XR to Raenok), Buzz & Mira fly off to save him w/ a newly developed cloaking device that can render 42 and/or its crew invisible. While attempting to sneak into the Raenok prison, Mira and Buzz spot Booster's folks, who heard about their son's capture and decided to attempt to save him. This allows the invisible Mira & Buzz to get through the first line of defense, while the capture of the Munchauser's provides a distraction. When they're attempting to figure out how to get through the second line of defense, Becky and her father, the Sheriff from Roswell, arrive (having also heard the news of Booster's capture). The capture of the Roswelleans provides yet another distraction. Finally, the LGMs also decide to help, which almost allows for Mira & Buzz to free Booster (...and XR, and Booster's parents, and the Roswelleans...), but they end