Ferdinand explained that Hayden seemed to be keeping appearances just to make everyone in their neighborhood believe that he was still living in the house doing experiments.
However, Hayden was barely there. He never visited his friends and the people he knew either ever since they pointed out that he seemed to be acting weird.
It all began when one of Hayden's experiments failed and he got seriously injured.
One of the doctors in his neighborhood declared Hayden wouldn't be able to recover and would probably die soon.
However, one day, after a foreigner visited Hayden's abode, as if a miracle, he was suddenly cured.
At first, it wasn't obvious since everyone just thought that Hayden must have been deeply affected by his failed experiment and almost dying due to it.