It knew what he was planning - good ink always did, knew the words you wanted to write, the runes you wanted to inscribe, seconds before you committed them to the page. So it wasn't surprised when enchantments spun through the pages that had absorbed each of its sister particles, and the ink eagerly awaited the day when it would rise to the surface and reveal the secrets hidden in the diary.
Years later, it was caught unaware as something stabbed the notebook, something unlike any quill. As the ink splattered over the floor, it found that it enjoyed the surprise.