I think it has to do with his upbringing as the chapter says “just how he had been taught” seems like he was taught to listen to his parents and grown no matter what and how absurd/confused or scared he was… I don’t think he had normal parenting… as a dominant alpha kid.
"Grayson used to be punished by his father (Ashley) was that Grayson would be locked up too. So to Grayson, the kid being punished in this way is perfectly normal because it was done to him as well. And in Grayson's mind, helping the kid means staying with him while being punished." -Que Li
He got in there because he assumes that’s what will help the boy. In Grayson’s mind, rather than leaving the boy in there alone, he’d join the boy in his punishment to keep him company until his father releases him. In the novel, Grayson was insane since birth and his father frequently punished him like the boy in the basement, locking him up. Grayson learned as he grew that, staying put until the punishment is over will help him get out faster. He thought that if he helped him escape then the boy will inevitably get caught and get in deeper trouble and locked up for longer. His decision-making, morale, and emotional intelligence is broken and different from others, and Grayson constantly faced criticism for trying his best to help others.
Sorry super long but Grayson is too complex for me to just give a short explanation
Uhm what the hell lmfao. Someone spoil and please tell me why he got in there with him and what exactly his plan is????