The Neo Zeon remnant group, "The Sleeves", travels to Side 4's Industrial 7 colony, so that its captain, Zinnerman, can meet with the Vist Foundation leader, Cardeas Vist, to receive a "key" to something known as "LaPlace's Box", which is said to be capable of either restoring the future, or destroying the world. Audrey Burns seeks to meet Vist first and convince him not to turn over LaPlace's Box, believing the Sleeves will use it to start another war.
With Banagher Links as its master, the Unicorn Gundam goes into action. The mobile suit that is said to be the key to Laplace’s Box offers a glimpse of its incredible power in single combat against Marida Cruz and her Kshatriya.
In order to recapture Banagher and the Unicorn Gundam, the Federation Forces launch an assault on Palau, the stronghold of the Sleeves.
The conflict surrounding Laplace's Box has spread to Earth, and even the Earth Federation capital at Dakar is now suffering from the terrors of war. Ronan Marcenas, a leader of the Federation government, contacts Londo Bell commander Bright Noa in order to prevent the opening of the Box. At the same time, the captured Marida is at the Augusta Newtype Labs.
Meanwhile, Banagher has landed on Earth, and is headed for the Torrington base in Australia where new information about the Box will be disclosed. However, the fury of Zeon remnants will head for Dakar led by the AMA-X7 Shamblo to turn the city into a wasteland.
Banagher is attacked by the black mobile suit Banshee and taken into custody. Backed into a corner, he still continues to conceal the new coordinates leading to Lapace's Box which were revealed by the Unicorn Gundam. Bright Noa, the commander of the Londo Bell, sees in Banagher the dignity and possibility shown by generations of Gundam pilots, and he finds help from old friends he once fought beside.
Meanwhile, Mineva has been handed over from Ronan to Martha, and she is transferred to the giant transport plane Garuda as a pawn to make Banagher talk. The conflict surrounding the Box soars to a high altitude and, finally, back into space...
Having escaped the pursuit of the Earth Federation fleet thanks to Full Frontal’s intervention, the Nahel Argama is now forced to form a joint front with the Sleeves. Frontal, hoping to learn the next coordinates for Laplace’s Box, reveals his secret plan against the Federation. Banagher and Mineva are horrified by the cruelty and callousness of the future he describes. Meanwhile, a lone Federation patrol ship approaches the Nahel Argama.
The location of Laplace's Box, which has the potential to overthrow the Earth Federation government, has finally been revealed. The place is Magallanica at Industrial 7, where the whole incident began.
Martha Vist Carbine, the acting head of Vist Foundation, is determine to protect the Foundation's interests. Together with her nephew Alberto Vist and Council on Colony Relations Chairman Ronan Marcenas, a central figure in the Earth Federation government, she heads directly for the Cheyene base in order to resolve the situation.
Meanwhile, Banagher is hurrying to Industrial 7 in pursuit of Full Frontal, who has gone ahead to seize the Box. But standing in his way are Riddhe's Banshee Norn and Angelo's Rozen Zulu.
Who will reach Magallanica where Syam, the guardian of the Box, is waiting?