10 Actors Who Appeared In Star Trek AND Battlestar Galactica

5. James Callis

Double the Baltar, double the Star Trek connection. Lord Baltar of the original 1978– Battlestar Galactica was played by John Colicos. Colicos was famously Klingon Kor in Errand of Mercy, returning three times with the ridges in Star Trek: Deep Space Nine. Drop the 'Lord,' add a first name, the reimagined BSG's Doctor Gaius Baltar was then portrayed by actor James Callis.

Without giving too much away, Baltar plays a pivotal role in the reimagined Battlestar, and that from the start. Though in far fewer episodes, Callis' turn in Trek was no less crucial. In Star Trek: Picard's second season, Callis took on the part of — the recollection of — a younger Maurice Picard (father of Jean-Luc). An older Maurice had previously appeared via the ministrations of Q in Star Trek: The Next Generation's Tapestry, played by Clive Church.

It would be tough to draw parallels between Maurice and Gaius. The former was a largely misunderstood man with an aversion to replicators. The latter was a prominent computer scientist of the Twelve Colonies whose hubris — and frakking — directly led to the Fall.

Gaius was no moustache-twirling villain, however. He was every bit the genius he claimed to be, but, like us all, he was flawed. The series skilfully played on traitor versus troubled throughout.