WARNING: The following contains spoilers from New Mutants #19 by Vita Ayala, Alex Lins, Matt Milla & VC's Travis Lanham, on sale now.
During the "Reign of X" era, multiple mutants have fallen under the sway of the Shadow King, a malicious and villainous telepath with power capable of standing up against the likes of Charles Xavier. While Anole, Rain Boy, No-Girl, and Cosmar have all begun to see the merits in his "teachings," Wolfsbane has also been taken in by his promises to help her find a way to reunite with her long-missing son, Tier.
One of their friends though, Scout, has become increasingly concerned with how her friends are acting as a result of his influence -- and that wariness might have just cost Scout her life, setting up a host of new potential conflicts on Krakoa.
During the Hellfire Gala, a few of the gathered mutants were confused as to why Scout hadn't arrived to make her way through the buffet. This particularly perturbs her elder sister Laura, who approaches Daken about her absence. Since coming to Krakoa, Daken has become increasingly close with the pair, forming something of a genuine family unit with them and Logan. He also hadn't seen Scout at the event and agreed to keep an eye out, reasoning that she was pulling a prank of some kind. But in reality, it turned out that the Shadow King had captured Scout -- even seemingly killing her and leaving her body to be discovered by her friends.
Given his own psychic abilities, it's possible he's even attacked her in a way that would make normal resurrection difficult. But his attempt to cover his tracks may have fallen into some serious problems, as Gabby's pet wolverine is able to find Laura and deliver a letter from Gabby. In it, she describes her intention to confront her friends one last time (which she did in the previous issue of New Mutants), trying to convince them to leave an unnamed someone and not let him figure out how to control and mold them. This is a strong implication to anyone reading it that someone is targeting the New Mutants and that Scout could easily end up in their crosshairs. The letter also indicates that she fully intended to attend the Hellfire Gala, and that her absence was not of her choosing.
While she may not have directly called out the Shadow King in her letter, there's enough evidence suggesting he was involved that it shouldn't be long for the X-Men to figure out what happened to her -- especially considering that a psychic attack would be one of the only ways to stop Scout considering her healing factor. It's likely that Shadow King has just painted a very big target on his back, especially now that Laura has been elected to the formal X-Men team and can try to direct the team's attention in the direction of the attack on her sister. Likewise, it's possible that Scout's recent conversation with Warpath might illuminate this attack a bit more as well, giving the New Mutants reason to investigate their recent connections.
This might also further incriminate Wolfsbane -- who actually helped lead Scout straight to the Shadow King, although it's possible she wasn't aware of just how far Shadow King was going to take things. Overall, this threatens to send ripples through the New Mutants and potentially break apart the long-standing friendships at the heart of the group while also likely setting off a conflict over the Shadow King's actions, which in turn could cause more fallout across Krakoa. Notably, the possibility of reviving Scout -- a clone -- also raises questions she herself had previously addressed about the limits and rules of resurrection. If clones like Scout are allowed to be revived, then it could give Havok more arguments that Madelyne Pryor should be restored as well -- which is worrisome, considering the fast approaching Inferno.