This short story series is based on what I believe Arcane could have been with a happier ending.
"Welcome to the Playground"
On the bridge war happened between Piltover and the undercity two sisters Powder and Vi lost their parents in the war and Vander, leader of the rebellion took them under his wing. Years later Powder and Vi along with their adoptive brothers Mylo and Claggor sneak topside for a heist they robbed the apartment. Powder found some blue crystals she dropped one of them and they exploded causing to break part of the apartment.
The four were chased by enforcers and escaped to the undercity where they ran into a gang after Mylo mentioned they stole stuff. Powder ran with the loot but dropped it into the river much to Mylo's anger. Mylo accuses her of "jinxing" every job. They returned home where Vander already gotten word of the heist. Vi shows her anger about the enforcers and topside getting everything they want while they have nothing.
Vander told her the more violence they because they make trouble for the enforcers much to Vi's anger. Vander took some stuff and heads to Benzo and Ekko. Enforcers Grayson and Marcus arrived to arrest those to rob the apartment Vander refuses to give up anyone. Powder was thinking about the job she went to a lookout point and looked over the whole city and remembered she has the crystals still. A cloaked figure sits right next her and he offered her a path of happiness which despite being told not to trust strangers she accepts his path he has planned for her.
Meanwhile Silco a crime lord has his men create the drug Shimmer.
"Some Mysteries are better left lost"
Jayce a scientist who was the owner of the apartment and was saved by magic when he was a child was arrested for illegal use of magic. Meanwhile Powder and the others were hiding out in an old arcade but they were found by enforcers they were chased.
The cloaked figure Powder met lead them to an escape path which as a dead end but the enforcers didn't seem to noticed them and the cloaked figure waved a "see you later" to Powder but the rest of the group didn't notice him.
Meanwhile Marcus is contacted by Silco who informs them that Vander's children are the ones who committed the heist leading Marcus to try to search Vander's basement but found no one. Vi expresses her desire to fight the enforcers but Vander reveals if he hadn't led the rebellion then her parents would still be alive.
Vi decided to turn herself in much to Powder's sadness.
Meanwhile Jayce almost commit suicide for failing to gain any allies in his research, but Viktor believes in him and becomes his partner.
"The Base Violence Necessary for Change"
Vi was waiting for the enforcers to arrest her but Vander plans to take her place. But Silco and his forces ambushed them killing all of the enforcers but Marcus they killed Benzo. Jayce and Viktor were trying to figure out how to stabilize the crystals.
Vi returned to the others explaining what happened and told Powder to sit this one out believing she's not ready but deep down thinks she's a liability leaving Powder heartbroken.
Silco took Vander back to his hideout where he reveals his plans to scare Piltover into giving them their independence. Powder has a mental break down feeling she was hated by everyone including her sister. She remembers the crystals and believes she can help them. Jayce and Viktor invented Hextech. Vi and her group found Silco's base. Silco plans to kill them under the rumor that Vander and his children fled town.
Vi fought the thugs, Mylo works to free Vander, and Claggor works on a escape. Powder followed them and began her plans. Powder makes a monkey bomb with the crystals, and it exploded but killed Mylo and Claggor, injured Vander who used Shimmer to save Vi before dying. Powder reveals to Vi she made the bomb but Vi stood in silence about their family's death Powder cries she only wanted to help. Vi hits her and finally declared that Powder is a "jinx". Having had enough of Powder's screws up Vi leaves her Powder begs her to come back and that she needed her.
The cloaked figure was watching them he had a small device on his left arm and said into it to take Vi. Silco found the crying Powder Vi saw this and attempted to save her but however the cloaked figure's men kidnapped her telling her all she knows what to do is cause pain. Silco asked Powder where is Vi but Powder lungs at him telling him she's not her sister anymore as she feels she was hated by her family.
Silco comforts her and vows to seek revenge on those who wronged the two. Powder knew she died this night.