Star Trek: 10 Characters Who Must Return (2023)
6. Yellow Cube Moriarty And The Countess Regina Barthalomew
Yes, yes, Moriarty has already returned, but that was hardly him. Even if it was fun, his appearance as a gunslinging Daystrom (Data) defence device in Star Trek: Picard's The Bounty doesn't fully count, and Descartes would no doubt agree. For the OG sentient holoprogram, we have to go back to that yellow cube in a memory module in The Next Generation. We just hope Barclay was holding on to it really tight as the saucer section slammed into Veridian III.
For a character that only featured in two episodes (and a half now), the Professor is insanely popular amongst fans (and rightly so). Credit to Conan Doyle in the first place and the TNG writers, as well as to the delightfully duplicitous performance from the multi-talented Daniel Davis. Speaking recently to the Trek Untold Podcast, Davis revealed that he accepted the part in Picard on the spot without even knowing what it was or seeing a script and had a great time during filming. That bodes well for him to play the geometrically imprisoned Moriarty again.
What also tends to be forgotten when Moriarty is mentioned is that there was another character in the cube with him: the Countess Regina Barthalomew, played by the magnificent Stephanie Beacham. If the cube did survive the destruction of the Enterprise-D, and if their relationship didn't go sour aboard the simulated shuttlecraft, they'd presumably still be a package deal for a return to the real world.