Where did my master go?

There once was a sentient Homunculus shaped like a cat.
As his master was a scientist, they often traveled, gathering samples of Elements. They were coworkers and great friends.
One day, the master got informed about an interesting phenomenon happening nearby.
The two of them gathered their supplies and left to investigate the occurrence. Just like the rumor said, they discovered the lights. Truly, an enchanting view.
The scientist started complaining about headaches and sounds calling to him, but they decided to move forward.
At some point, the cat turned around.
There was no one beside him.
His master disappeared.