"Locked Room Misery"
The Mystery Inc gang go to investigate a robbery at Freddie's Uncle Ned's traveling circus. Someone has been stealing the ticket money every night after Uncle Ned has locked it up. The gang searches around the circus and discovers that the culprit is Ringmaster Rick and his flea circus.
"Sound Stage Spook"
Reprinted from Scooby-Doo (1997) #18.
Scooby and the kids are invited back to the movie studio where they've already solved one case. But now there is a new spook loose on the set and its up to the gang to solve it. The phantom of Clayton Lonney is loose on the set and threatening to ruin a movie shoot but the gang snoops around and exposes the phantom as a rival film maker Lucas Spiegel. They both were making monster films and Spiegel wanted to get his in first.
*A circus owner hires the Scooby Gang to figure out how someone is spiriting away the box office receipts at his show. Shaggy and Scooby opt to get locked in the office and discover the door is silently unlocked...by nobody! Zoinks! *Source: dccomics.com