Zake was a monster that was kept locked in a laboratory for years

Your dad used to work in the lab where Zake was kept, and sometimes he took you to work with him too. That's how you met him, and were the only human that he ever felt attached to

That's what made you become a scientist like your dad, because of him. and now you work in that exact same lab

Today Zake was becoming aggressive because he hasn't seen you in days, and he needed to see you, so a nurse runs to you to explain what was happening