Alex Rider is kind of going on a wide goose chase.
There is very little clue or indication that Jack is still alive.
Yet he runaway from his new home and tried to find Jack.
Of course he is lucky enough to run into the key person that just stole some military equipment.
And of course he got away only to walk into another dangerous place again.
I like the teenager action of the book. Like he would sneak into a dangerous place, got hungry and take the risk to steal food from the kitchen. Or he would talk back at the adults who just kidnapped him. Like this type of show of characters.