Alex knew K-Unit before the Point Blanc Mission, it was a mission assigned to him while within their care, and he doesn't go because of his uncle's death. He agrees because Blunt threatens to take him away from the unit for good. He's able to convince them to let him go, that it's just an in and out mission (or so he thought),only if anything goes wrong he must contact K-Unit immediately and they'll come get him themselves. Alex reluctantly agrees.
He's placed in a wealthy family's home undercover, forced to act as a disobedient son to get accepted into Point Blanc Academy, school for troubled children, to observe and report back to MI6 on just what they're up to. Two parents with children who attended the academy were mysteriously pronounced dead, and he has to find out why.
Things don't quite go as planned, and the Academy's methods may be a bit more ruthless than expected.
Above is the full summary of an idea I had after watching the new Alex Rider show based off the book Point Blanc. This is not the first chapter, the first chapter has been posted, check it out! :)