There are 5 stars that are particularly difficult, and Brown has 2 of them, Algol and Zosma, affecting the prime of his life. What makes them even more difficult is that both have ‘curtailed passage�?i.e. he was born at a place/time where neither of them rose or set, so they do not have any contact with the earth, with human affairs, and are therefore more likely to manifest in a fated sort of way.
This is even more the case with ALGOL, because it is linked to his Sun, his very identity. Early writers all viewed Algol as the most malefic star in the heavens.