In the library, he found a book on curses and grudges.

Rather, a treatise on 'unintentional malicious usage of post-unification magecraft'.

It was getting late, and he had almost given up. He hadn't planned to stay much longer.

He took the book from the shelf and went to sit at the table, alone.

And he opened it, and he read it.

Before the continent was re-unified by the migration of Altaer, it had not been possible to use magic unintentionally.

But by the time the distinctions between 'aether' and 'lyneal' magic had become obsolete, it became theoretically possible.

A lasting hatred that persists beyond death... A grudge, or sometimes, something stronger, a curse. Magic that coalesced like a maelstrom around the intense emotions of the deceased.

But they were very rare, and difficult to study.

The treatise, slim, only contained a few cases, all of which concerned powerful mages.

...The Demon Lord Vasyra was a powerful mage; one of the world's most powerful, if not the most...

Was it possible he had left some kind of grudge that had dragged Henry back to the past?

If so, why did it take so long for that to happen?

He couldn't find an answer.