Ray was certain about this because it was the only thing that made sense to him.
Sera had to have known something really important about that spell and possibly about Elise and her father as well, forcing them to get rid of her, despite the young lady being one of the few healers in the kingdom.
Thinking back now, since Sera was caught three years in the future, it meant that it took Elise and her father that long to find her, so that means if Ray wanted to find her, it would definitely not be easy for him to do so either.
Ray stared at the ceiling as his mind began to race while he pulled more details from his previous life.
Back then, while Elise had bragged about how Sera had been killed, Ray recalled hearing a few piece of information that hadn't mattered then but had mattered enormously now.
First of, Sera wasn't just any healer anyone could find anywhere.
