These summaries were written before the English version of these episodes was made. Therefore some character names do not match the names that were eventually used in the English TV version.
In episode 74, Sailor Moon defeated Rubeus and he was destroyed. Several Dark Moon Family villians remain. They are Esmeraude, Saffir, and the eldest brother, Prince Dimando. The Prince is advised by the mysterious Wiseman, who seems to have a secret agenda of his own. The present-day Sailor Scouts don't know about Saffir, Dimando or the Wiseman, but they have learned of the existence of another ally, Sailor Pluto.
The Sailor Scouts of the future have combined their power to block the Dark Moon assault. Prince Dimando sent Rubeus into the past to weaken Crystal Tokyo by planting Dark Energy into areas that would be key points in the future city. After Rubeus fails, Esmeraude asks Prince Demand why he doesn't simply use the power of the Dark Crystal to destroy Earth in the past. Demand explains that he is not able to send that much energy into the past. Esmeraude proposes that they tap into the Negative Energy that already existed in the past to open a Dark Gate. The Gate would let them take the Dark Crystal into the past and destroy the Earth before Crystal Tokyo ever exists. Esmeraude travels to the past (our present) to attempt this new plan.
In episodes 76-81 the Sailor Scouts fight to destroy the "Dark Hedges" that Esmeraude places in Tokyo. These Dark Hedges open points of Negative Energy. If enough Negative Energy points are opened, the Dark Gate can form. Each Hedge is protected by a droid. In episode 81, Esmeraude plants two Hedges and the Scouts are barely able to win against two droids at once. In fact, they are only saved when Rini uses her Moonbeam power. In the future, the Wiseman advises Prince Dimando that they should capture "The Rabbit" and add her energy to the Dark Crystal.
At the end of episode 81, Rini and the Sailor Scouts decide they must travel to the future, confront the Dark Moon enemies, and save Rini's mother...