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Tear Jerker: Static Shock
"Flashback" a time travel episode in which Virgil goes back to meet his deceased mother on the night she died in a gang riot as a paramedic/EMT caught in the crossfire whilst trying to save lives. Virgil reveals his secret identity as Static to her and begs her to stay out of harms way so she doesn't die this time, painfully explaining his reasons - though he doesn't explicitly mention she is destined to die but mentioning she will be hurt. However, her desire to help people drives her back onto the streets even though it's implied she has figured out why Virgil gave her such a dire warning. His panic as he sees her with her ambulance crew amongst the fracas as he is stuck in the time bubble that returns him to the future is heartbreaking, made even worse when he runs home with the faint hope he succeeded only to discover she still died.
Adding to that is the reveal of what did change: on the night she died, Virgil's mother told everyone how her son was a hero and she was proud of him.