Thursday’s TV highlights

SERIES

World’s Toughest Fixes: Sean Riley travels to Britain to help repair three iconic bridges, including London’s Tower Bridge, where the restoration includes stripping away and containing lead paint (6 and 9 p.m. National Geographic).

The Vampire Diaries: Elena (Nina Dobrev) frets about Jeremy (Steven R. McQueen), who in turn is worried about Anna (Malese Jow), especially her latest plan for the future. Matt Davis, Ian Somerhalder and David Anders also star in the season finale (8 p.m. KTLA).

Supernatural: With the apocalypse looming, Dean and Sam (Jensen Ackles, Jared Padalecki) realize they have run out of options and make a decision that will change their lives forever in the season finale (9 p.m. KTLA).

Grey’s Anatomy: Two long-lost lovers are reunited in the emergency room, which leads the staff to reassess their life choices (9 p.m. ABC).

Fringe: Olivia (Anna Torv) travels to the parallel universe with Walter (John Noble), who faces off with William Bell (Leonard Nimoy) in the opening hour of a two-part season finale, concluding next week (9 p.m. Fox).

The Mentalist: Romantic sparks fly when Patrick (Simon Baker) crosses paths with supposed psychic Kristina Frye (Leslie Hope) during an investigation into the murder of the charismatic leader of a nonprofit organization that fights human trafficking. Aunjanue Ellis and Nick Searcy also guest star (10 p.m. CBS).

The Marriage Ref: Howie Mandel and Bette Midler join the celebrity panel (10 p.m. NBC).

Private Practice: Addison, Amelia and Fife try to save Maya and her unborn child in the season finale (10 p.m. ABC).

MOVIES

Dances With Wolves: Kevin Costner plays an idealistic Civil War lieutenant who befriends a Sioux tribe in this Oscar-winning 1990 western. Mary McDonnell costars (7:15 p.m. TCM).

SPORTS

Basketball: NBA Playoffs: The Cleveland Cavaliers visit the Boston Celtics (5 p.m. ESPN).