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Susan calls 7-Zark-7 with alarming news that a weapon Spectra has been putting together on planet Riga is operational. The Federation has been aware of the construction for some time, but haven't been able to do anything about it. 7-Zark-7 puts G-Force on standby alert and also passes along a personal message for Mark - one of his old Space Academy classmates named Tom was found injured and was asking for Mark. Mark requests Tom to be sent to his airfield shack to rest.

A Rigan delegate passes along a message from Spectra to Chief Anderson – the Intergalactic Federation must surrender to Spectra, or they will launch their X-3 weapon. Mark meets with Tom back at his place and Tom casually mentions that Mark must be glad his father is still alive. Mark can't believe what he has just heard! Tom explains that he ran into Mark's father a week earlier on planet Riga. Mark is astounded... all these years he's been searching for his father and now there is word that he's alive and well. Mark tells Keyop he's going to Riga with Tom.

G-Force is called into action and Chief Anderson isn't happy when he learns Mark has taken off on his own. But the mission to stop Spectra's X-3 must continue. If the X-3 plan succeeds, it will destroy the Van Allen belts surrounding Earth which will allow deadly radiation from the sun to contaminate the planet.

On Riga, G-Force is immediately confronted by a deadly Spectra ship that looks like a wheel with blades on its side. Elsewhere on the planet, Mark follows his friend Tom into a building but the second he steps inside, the entire room descends underground. Mark has been set up. Tom is a Spectra agent! Back on the Phoenix, Princess gets an idea on how to activate the Bird Missiles. When she succeeds, G-Force is able to destroy the Spectra machine. When the ship is destroyed Zoltar realizes Chief Anderson is not going to surrender, so he begins the countdown to launch the X-3.

Mark, who is now a captive of Spectra is suddenly freed by Colonel Cronus. G-Force arrive at the X-3 launch site a hair too late and stand by helplessly as they watch it launch towards Earth. Jason is upset at Mark for adding to the difficulties, but Chief Anderson tells G-Force the real story behind Cronus and Riga...

Years ago when they first found out about Spectra's X-3 plan, Anderson sent his best test pilot to Riga to steal or destroy it. The man left his four year old son to Anderson, changed his name and took off with a team to Riga. The man was Colonel Cronus and the four year old boy was Mark. Anderson never told Mark the truth because Cronus didn't want it known. G-Force is shocked.

Back on Earth, the X-3 has arrived and triggered the Van Allen Radiation Belt to descend... Icebergs melt, tidal waves churn up and other disasters occur around the globe!

Tiny has been promising to go on a diet every year that Princess has known him

Mark went to a Space Academy when he was younger

Mark's father disappeared years ago, and Mark has never believed him to be dead

Princess devises a temporary method to allow the Phoenix to fire missiles without Mark's plane on board

Colonel Cronus is actually Mark's father

Note: Tom was originally named "Clifford" in scripts

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