It'll be interesting to see if the Prague group actually sees Stefano. Or if we (the viewers) only see him. Or if maybe he's a ghost or dream of another character, like Hope, Marlena, Andre or Chad.
On The Bold and The Beautiful, there was a crazy character named Sally Spectra. The actress who played her, Darlene Conley, died in 2007. But they've kept the character alive, by occasionally mentioning that she's on an exotic island, sipping drinks and eyeing up handsome cabana boys. Just thought it was an interesting way to keep the character alive, as well as the memory of the actress who portrayed her.