..To place a homing device in Center Neptune, to destroy it with a missile..
|..To find and destroy Zoltar's missile base before it is ready.
Spectra launches another attack and 7-Zark-7 sees the object land in one of Earth's oceans, not far from Center Neptune. Soon, a Spectra submarine surfaces next to a cruise ship in the middle of that ocean. A soldier appears from the top of the submarine and signals to Lothar, another Spectra agent on board the cruise ship. Once he sees the signal, Lothar sneaks into the engine room to plant a homing device.
Lothar escapes to the Spectra sub where he reports to Zoltar that the signal is loud and clear and the cruise ship can be their first target. Zoltar launches some new Spectra missiles which are tuned to the homing signal. As they close in on the target, Zoltar explains that next time they will use live ammo.
Meanwhile, G-Force is relaxing in their ready-room when 7-Zark-7 interrupts them with a red alert. Chief Anderson briefs the team about the missile attack. He also tells them that the attack confirms suspicions that Spectra was involved.
The team launches on their mission to find Spectra's missile launching base. Two kilometers from the strike point, Tiny takes the Phoenix underwater. Spectra launches some crab attackers and while they’re dealing with the diversion, Lothar secretly attaches his sub to the underside of the Phoenix. When the Phoenix enters its dock the sub releases itself from the Phoenix and attaches itself on the exterior hull of the research center.
The crew then take the sub to another docking area inside Research Center. 7-Zark-7 is now knows the sub has made its way inside Center Neptune’s defenses, but is unaware of where it is. The Spectra crew disguise themselves as scientists and look for a location to plant their homing device.
When they locate the Spectra sub, G-Force has a starting point to start looking for the saboteurs. They know of the plan to plant a homing device, so G-Force splits up; Tiny, Jason and Keyop leave in the Phoenix to find the missile launching base, while Mark and Princess stay behind to locate the Spectra soldiers.
The spies reach the heart of Research Center and place the homing device. One hit there will destroy the entire complex. Now that their job is finished, they head back to their sub. On their way back however, they are discovered by Mark and Princess, but they manage to elude them to get back to the sub and report their success to Zoltar.
Since the homing device has not been located, Mark says that their only hope is to find the missile base now. On the Phoenix, Jason says he thinks he has a good lock on the location of the base. But Zoltar launches the missile attack before anything can be done. Back in Research Center, Princess locates a signal that Chief Anderson identifies as incoming missiles... and there's no way to stop them.
be confident this time, since Susan notes they are making no attempt
to disguise their invasion or plans