Some of the smooth polished edges have been worn down in the four years the Enterprise-D has been traveling the stars, but “Ensign Ro” gives us a titular character with a checkered past and a dislike of all our regular characters. Another guest star has a checkered past in “Silicon Avatar” and it’s a giant space-faring crystal. Plus! Richard can’t wait for Star Trek: Deep Space Nine, starting on Trekabout in just 40 weeks!