I don’t understand what’s happening?? Can someone explain

Okaya set a bomb, send a letter warning that he would explode the school to the principal, making him think it was the regular threats he receives every year, but bc of the fireworks that were inside the letter he decides to take it seriously (except he doesn't want to call the police bc he's corrupted). In the warning, it gives them a hint of where the bomb is located, Maria immediately caught on to the bullshit the "hint" was, and followed logic instead of wasting time

Thank you! That makes more sense!!