Hal, Charles, and Mercedes die a terrible death in the "northern river." Their fate basically sums up what their time with Buck amounted to: weakness. London wants to make sure that his reader knows that the wild does not tolerate this kind of inept, superficial person.
B.Natasha is gathering information in the research part of the research process.
First of all make up can clog your pores and it can form pimples. Second it makes you look older and if you're young you can attract negative attention from older men. Third you should me happy with how you look. And fourth When you sweat or cry your make up smears and then you look like a drunk zombie.