Why does Harry become suspicious of Draco Malfoy in "Harry Potter and the Half-Blood Prince"?
Because he overhears him discussing a mysterious task.
<s>[INST] <<SYS>> Answer as briefly as you can to the following question. You are required to give a one-shot answer: <</SYS>> Why does Harry become suspicious of Draco Malfoy in "Harry Potter and the Half-Blood Prince"? [/INST] Because he overhears him discussing a mysterious task. </s>