[gmw]

Does anyone have any idea of the correct way to punctuate the following sentence (names changed to protect the innocent). The scene is of a character sitting in silence thinking about his friends:

Abby was gone, and Bill was who knows where now.

It's not actually a question, so a terminating question mark seems wrong. Older texts had no qualms about extra punctuation in the middle of a sentence, but it seems that more modern works shun the idea. Otherwise I was thinking something like this might work:

Abby was gone, and Bill was who-knows-where? now.

Any suggestions on what would be considered correct?