PRETTY LITTLE LIARS: A wrench is thrown into the plan when Ezra tells Aria about his concern and suspicion of Spencer's recent addiction problem. (Adam Rose/ABC FAMILY)

Tonight’s Winter Olympics (NBC at 8 p.m.) coverage includes women’s giant slalom, women’s bobsled, men’s freestyle skiing finals (halfpipe) and women’s short track.

In its first live show of the season, “American Idol” (Fox at 8) has the top 15 female vocalists perform.

Spencer misses an opportunity to share her doubts about Ezra with Aria on “Pretty Little Liars” (ABC Family at 8) once Ezra brings up her addictions.

The “American Experience” series takes on a New York landmark in “The Rise and Fall of Penn Station” (WETA at 9), a look at the legendary building built for the ages in 1910 but unable to survive the financial woes of the Pennsylvania Railroad and its demolition in 1963.

Todd is in big trouble on “Dangerous Grounds” (Travel at 9). When he has to smuggle coffee out of Thailand in order to successfully expand his cafes in the United States, Todd runs into problems at the border with Myanmar police.

Following last week’s finale, “Shahs of Sunset” (Bravo at 9) airs part one of its two-part third season reunion, with Andy Cohen as host.

FINALE WATCH: “100 Days of Summer” (Bravo at 10) wraps up its first season with Tina inviting the gang to a family cabin in Wisconsin and, as expected, a weekend of relaxation turns into a weekend of road-trip rage and divided friendships.

Molly is forced to work with a sexist, retired Texas Ranger after an arrest she makes leads to a tip to an unsolved murder he wasn’t able to close years before on “Killer Women” (ABC at 10).

RETURNING SHOW: Back for its sixth season of insane Internet videos and commentary, “Tosh.0” (Comedy Central at 10) continues with a resurrection of “Sports or Consequences” and a sexy “Web Redemption.”

For the “House of Cards”-obsessed, a.k.a. those of you who are already done with its second season, Kevin Spacey will be on “The Daily Show With Jon Stewart” (Comedy Central at 11).

Olympic gold medalist Sage Kotsenburg (men’s slopestyle) and actress Kate Mara stop by the “Late Show With David Letterman” (CBS at 11:35), along with music from Cole Swindell.

Comedians Jerry Seinfeld and Kristen Wiig are on “The Tonight Show Starring Jimmy Fallon” (NBC at 11:35), with a sure-to-be-talked-about performance from Lady Gaga.

Political commentator Bill O’Reilly comes to “Jimmy Kimmel Live” (ABC at 11:35), along with “Game of Thrones” actor Kit Harington and music from the band Phantogram.

Rachel Lubitz