The environment portryed in the Mercury comics, as well as a majority of others, is perceived as taking place some time around the 60's-70's.
19XX - Susanne Ray, prodigy wiz kid, is exposed to a peculiar chemical compound that alters her and gives her superhuman abilities including pyrokinesis, superhuman strength, enhanced durability, and flame generation.
19XX - Susie takes it upon herself to defend the city as the super-heroine, Mercury.
19XX - Susanne makes her first arch-foe, Fire-Hazard, the very maniac that caused the accident in the first place.
19XX - Susanne begins to work as an intern for the company that her mother works under.
19XX - Susie's best friend, Ariel, discovers her secret.
19XX - Susie meets David James who she eventually begins to date.
19XX - Mercury encounters a new arch-foe by the name of Toxin who her fire powers have no effect on and whose skin is highly toxic, preventing her from touching him.
19XX - Mercury joins forces with Flip-Side, Scarecrow, Half-Ghost, and Diamond-Girl to stop Zoa who had taken control of Golem 2.0 and was using him to break into an abandoned A.M.M.O bunker not far from Manhattan that had a transporter device that could bring the mighty devil to Earth.
19XX - After angering Devil-Bat enough to the point where he breaks the mental hold Zoa has over him, the five heroes decide to band together again should it ever be necessary, dubbing themselves The Warriors and claiming the bunker as a base of operations.
19XX - Mercury successfully prevents an invasion of parasitic aliens that bring out the worst in their hosts by torching the queen and her nest.
19XX - Mercury discovers after a number of episodes regarding her unusually dark behavior that she'd been intruded by one of these parasites and fights for dominance.
19XX - While fighting Toxin who'd captured several scientists he was rather angry with, Mercury continues to fight herself, her darkest of inner desires but a lab explosion separates her from the parasite...and mutates the creature, turning it into a dark parallel of Mercury calling herself The She-Devil, one of Mercury's most dangerous of arch-foes.
19XX - Mercury takes up Ariel as a partner after she acquires superhuman water manipulation abilities.
19XX - Mercury meets Kenneth Drake.
19XX - David and Ariel are kidnapped by Fire-Hazard and Mercury sets off to rescue them.
19XX - Fire-Hazard leads Mercury to a small boat rigged to explode and throws an anchor overboard with the chain tied around David's leg, dragging him in. Meanwhile, with Ariel on the boat without her necklace, Mercury rushes to try and save them both. She fails to stop the explosion but absorbs the blast as best she can, protecting her friend from the flames. She then dives down into the water after setting Ariel down on a bridge. She is able to break the chain binding David but all too late. He'd drowned...he was gone.
19XX - Ariel loses her powers when the necklace is destroyed by Ice Empress.
19XX - At this low point in young Susanne's life, she begins to consider giving up as a superhero, leaving the protection of the city to those more suited for it like the Exemplar or the League of Heroes.
19XX - She holds out for a bit longer but things only get worse when her uncle returns after having been gone since she was four. He later discovers his Niece's secret and tries to use her as a tool to get back at several gangsters who'd conned him, later revealing that he was actually a notorious crime leader that Mercury had no choice other than to bring to justice. Unforunately, he'd supposedly died, falling from the bridge during a fight with Toxin.
19XX - Susanne gives up on being Mercury.
19XX - Susanne suits back up after a mentor of hers is driven over the deep end following the death of his wife, now altering himself and continuing on as Ion, a man of pure ionic energy.
19XX - Reminded that she is still needed in the world, Susanne reclaims her status as Mercury for good.
19XX - When Mercury rejoins The Warriors and begins to try and breach Scarecrow's estranged relationship with the others. But, in doing so, she grows attracted to him.
19XX - Mercury is honored by the New York public after saving the city from a rampaging New Golem (notably by tricking Golem into Central Park to tangle with Devil-Bat).