In Madame Web, we learn that Cassie Webb's mother was shot and killed by Ezekiel Sims after stealing the mystical spider she went searching for in the Amazon. The villain later used that to give himself powers, though we never actually find out why he wanted them.
Cassie's mom gives birth while dying and is helped by the mysterious spider-people who live in the jungle; they allow one of their spiders to bite her as she gives birth in an effort to save her life; it doesn't work, unfortunately, but is something which proves important down the line.
In the present day, an accident at work sees the paramedic Cassie gain precognitive abilities. Eventually, she crosses paths with teenagers Julia Cornwall, Mattie Franklin, and Anya Corazon, learning they're being pursued by Ezekiel after having a vision of their murder at his hands.
Since he was bitten, Ezekiel has been haunted by visions of his demise courtesy of three costumed Spider-Women. Using stolen NSA technology, he identifies them and sets out to kill the teens before they can do the same to him. This brings him into conflict with Cassie who, reluctantly, tries to save the trio.
After heading to the Amazon, she learns of Ezekiel's role in her mother's death and gains a better understanding of her newfound clairvoyance.
With a helping hand from Ben Parker, Cassie and the girls draw the villain to a warehouse full of illegal fireworks. A fight ensues and Julia, Mattie, and Anya are all at risk; pinned down by Ezekiel, she projects herself - Doctor Strange-style - and saves them. As for Ezekiel, he's killed by a falling sign after being lured into its path; it turns out his visions were actually leading him to this moment.
During the scuffle, Cassie falls into the water below and is hit in the face by an errant firework. Brought back to the shore, the three girls use the CPR technique Cassie taught them earlier to resuscitate their friend who now has white eyes after being blinded.
During the final few minutes, we see they've moved in with Cassie. She's rocking a nifty pair of shades and using a wheelchair; while her carers are currently powerless, a glimpse into a possible future shows them suited up with Madame Web's spectral form - also in costume and wearing even bigger sunglasses - floating above them.
Oh, and for those of you wondering, this version of Madame Web doesn't suffer from myasthenia gravis as that was cured by the spider which bit her mother (which is why she travelled to the Amazon in the first place). So, instead of being left blinded and wheelchair-bound by that disease, it happens as a result of her fight with Ezekiel. Yeah.
Madame Web is now playing in theaters.