..To use Princess' lost shoe as a means to discover G-Force's true identities..

..To keep Spectra from learning G-Force's secrets and get Princess' shoe back.

........

7-Zark-7 receives an emergency signal from a remote spot on Earth. Something strange has been sighted in a mountainous area and his scanners soon reveal a giant Imperial Mastodon breaking up from underground. But he knows this shouldn't be, as the creatures have been extinct for millions of years.

The Mastodon is actually another Spectra ship under the command of Zoltar. His target is the Earth Resource Center, located on the coast just behind the Joyland Amusement Park. He hopes to scare everyone away from the park and destroy the Resource Center before anyone knows what's going on.

It just happens that Princess and Keyop are enjoying a day at the park when the Mastodon attacks. The rest of G-Force rush in to help out and eventually succeed in driving the massive machine away. Yet in the middle of all the action, Princess loses her G-Force shoe. When she reports this to Chief Anderson back at Center Neptune he is extremely upset with her. Without the shoe, Princess can't transmute into her G-Force uniform and Anderson tells her she's useless to the team.

Unfortunately for G-Force, a Spectran worker discovers Princess' shoe jammed between the toes of the Mastodon. He throws it into an incinerator and later notices it intact and unharmed. The finding is reported to Zoltar who orders it to undergo a battery of tests. The shoe stands up to everything until hit with massive levels of radiation... then it shimmers and transforms into Princess' G-Force boot. Zoltar orders his scientists to figure out how to use the information to their advantage. The scientists come back with a mannequin in the rough size and shape of Princess.

Zoltar's next step is to persuade Tomorrow's Woman Cosmetic owner Madame Demain to come up with a fake contest. The contest uses the outline of the Princess mannequin, in which hopeful contestants will try to fit, to determine the next Tomorrow's Woman. Princess tries out and fits the form, as do a handful of other girls, who are quickly knocked unconscious with gas. They are then delivered to Spectra's hidden base. While she's on board the ship pretending to be unconscious, Princess taps her Wrist Activator to send an emergency signal to G-Force. They receive her signal, but then Princess has to stop tapping to avoid being noticed, so they lose it. However, it gets the team close enough so they’re sure they'll find her.

Zoltar takes a close look at the girls in the Spectra base, but just before he gets to Princess an alarm sounds the arrival of G-Force. Princess uses the distraction to break herself and the other girls out of the cell. As they're making their way through the base, Princess finds her shoe. When she grabs it, it sets off yet another alarm and Zoltar is able to block their escape. As Zoltar threatens the girls, Mark, Jason and Keyop break into the base and confront the evil ruler. He orders his men to rout G-Force while he, of course, runs away.

Mark throws his boomerang after Zoltar which only snags part of his cape. But G-Force manages to get the girls out of the base. Before leaving, Mark throws a homing beacon onto a wall of the base to attract any of Spectra's missiles back to their source. G-Force board the Phoenix to get away and Zoltar fires missiles at them from his Mastodon machine. As expected, the missiles double back and destroy both the Spectra base and Mastodon. Zoltar orders an evacuation and he and his men are able to escape again.

Princess' shoe is impervious to most elements

G-Force's transmutation technique uses radiation

Without their entire outfit of clothes, G-Force is unable to transmute into their G-Force uniforms

.