Cleithrophobia.

in seoul, there is an art museum called the 'nuit étoilée' or 'starry night' art museum. it's a worldwide attraction, with art styles which interest all ages. however, there's something... strange about it. taehyung knows. he is a detective for the case called 'disparu'. he has been sent to investigate the weird disappearances of the people around seoul who visit this art museum.
it's a private case- hasn't been told to the public yet, but taehyung has been silently watching over one painting which seems to have caught his eye. it is decorated with blue trees, and a white background.
he seems to hear... voices? no, it couldn't be; it was attached to a wall...
but he could, they were clear; two distinct voices.
taehyung reached to touch the painting- and pain shot up his arm. he could reach through it, but whenever he tried to it would cause excruciating pain....
what was this painting? and why did it seem to have people inside it?