This episodes shows Hotaru has lived peacefully with her father for maybe half a year at best. A familiar figure (we all know it is Setsuna!!!) shows up and takes her way, hinting a crisis is about to happen.
Also living out a peaceful life, Haruka and Michiru soon appear. Yes, they are still together even though their mission is over and they haven't been needed as soldiers. Sure, Usagi and company are together after becoming soldiers, but they live in the same town, go to nearby schools, have duties to protect their princess and prince...
There could be the argument that Haruka and Michiru are just friends hanging out, but context in their dialogue soon puts that to question. At an aquarium, they are watching the fish. The settings are dark, quiet and peaceful. Haruka notes how Michiru really likes it there. She agrees by saying she feels relaxed watching and could stay for hours. Haruka replies she feels more comfortable behind a steering wheel. This makes Michiru laugh and she notes, "Silly, I wasn't talking about the fish!" This of course dumbfounds Haruka.
They both step outside - a viewer may notice there are only couples about. They notice the "falling stars" and Michiru makes note of dark energy near the moon, but can't get anymore information due to it disappearing quickly. Haruka believes it is nothing. Michiru is surprised by the other's optimism. Haruka says it is because she believes in Michiru.
As they look at the stars again, Michiru's head is leaned in close to Haruka - it is a rather romantic image. The "star shower" stops all of a sudden. Many people are suddenly crying out in pain and soon enough Haruka does as well. A glass shard entered her hand. Michiru quickly kneels down, takes the other's injured hand and gently sucks the shard out of the wound with her mouth. The action greatly resembles a kiss of the hand.
The shard soon explodes and a glass formation begins to appear - it takes on the shape of Nehellenia. Many other shards that had fallen soon do the same. They are surrounded, but soon enough Sailor Pluto makes her official appearance.
Haruka and Michiru quickly recognizes her powers and voice, utterly shocked that she is alive and well. (They did see her die in S season.) Pluto gets down to business, no time for explaination to her presence for the time being, and tells them of a distortion in the timeline. That is good enough for the other two, until Haruka notices the bundle in Pluto's arms.
"That child, is it Hotaru?" she asks. Michiru gasps at this. Pluto bows her head sadly and admits she took Hotaru from her father, but only for a little while. Now this leads to demanded answers. Haruka is angry and demands to know Pluto would do such a thing. This small scene alone shows Haruka cares about Hotaru. Just like for themselves, they wish for Hotaru to live a happy, peaceful life with her father.
Pluto obviously feels the same, but is definitely insulted that Haruka would think she would do such without good reason. Her brow furrowed, she explains urgently that they will need Hotaru's power as Sailor Saturn. As shown, even after putting their full faith in Sailor Moon, no matter their feelings, no matter what position in life they are, they must become soldiers when it is necessary. Even though Hotaru is still an infant, she is still expected to follow her duties in some way or another. She isn't expected to fight in such a state of course.
Their discussion is soon interupted as the enemy regenerates. Pluto carefully places Hotaru into a hiding place. She eyes the child gently, kindly and murmurs, "It's too early for you to fight." (Like Haruka, Setsuna is such a softy when it comes to children.)
Transforming, the three Outer Solar System Soldiers take to battle. During a small rest period while the destroyed enemy regenrates, Uranus is quickly taken be surprise and is pushed off the rooftop of the towering building they are on. Neptune manages to catch hold of her wrist. They are then left in a precarious position with her halfway over the ledge and Uranus hanging with all her weight reacting to gravity.
Despite dire situations, Uranus and Neptune tend to make jokes during such dangerous situations. Neptune makes note of Uranus eating too many sweets lately. Uranus quips, "I don't listen to that kind of talk outside of bed."
Their distraction is soon cut off when they hear Pluto cry out Hotaru's name desperately. Uranus's eyes constrict to small dots. Neptune turns to look. Pluto is trapped by an enemy. Her eyes, though not as constricted as Uranus', are small with fear. Persperation from anxiety forms on her face as she cries out, "You must not harm that child!"
Yes, one of their opponents discovered Hotaru's hiding place and the three acting soldiers are trapped in positions that prevent them from protecting her. All of them beg for the creature to stop. Though Uranus cannot see what it happening, she knows enough. She cries out the hardest, "Stop it!" I make note of this, because it is after Uranus' harsh cry does Hotaru awaken from her sleep. A flash of light errupts from Hotaru and soon her planetary symbol appears on her forehead.
The three Outer Solar System Soldiers are soon elsewhere, a void where they are floating back to back with each other. Their transformations undone, they are covered in ribbons. They are surroudned by a warm energy that is Hotaru's power. They take note that a new power is born and they suddenly power up to Super Sailor Soldiers.
While "a new power is born" definitely refers to their power ups, I also believe it refers to Hotaru's role as Sailor Saturn. Yes, it signals that Sailor Saturn had to be reborn into their world due to a new crisis, but I believe it also refers to Saturn receiving a new power that allows her to act beyond her single role as the Soldier of Destruction. She now has the power that will allow her to act as a Sailor Soldier that is necessary for all times of crisis and not just when the end of the world is necessary.