"Castle"

DRAMA. It's a "Firefly" reunion when Adam Baldwin guest stars as a gruff gang-squad cop whom Castle (Nathan Fillion) chooses to shadow.

10 p.m., ABC

 

"'Eden's World"

REALITY. Retired pageant competitor Eden Wood, the 7-year-old former star of "Toddlers & Tiaras," shares her pageant world wisdom with little girls aspiring to be just as exploited as she is.

Series premiere, 10 p.m., Logo

 

"Eureka"

DRAMA. The final season of this fun Syfy drama kicks off with the missing Astraeus crash landing. Allison and the crew are shocked to find themselves back in Eureka — and even more surprised to learn four years have passed since they first left.

Season premiere, 9 p.m., Syfy

 

"Top Gear"

REALITY. The guys travel through India in the Season 18 premiere of this U.K. hit, three classic British cars in tow and one death-defying stunt planned for an overnight train ride to Jaipur.

Season premiere, 8 p.m., BBC America