Welcome back to Tune In: our weekly newsletter offering a guide to the best of the week’s TV.

Each week, Variety’s TV team combs through the week’s TV schedule, selecting our picks of what to watch and when/how to watch it. This week, “Scandal” hits a television landmark, while “Girls” airs it series finale and the final season of “The Leftovers” begins.

“Scandal,” ABC, Thursday, 8 p.m. 

In the landmark 100th episode of the Shondaland series, Kerry Washington’s Olivia Pope and her crisis management team will explore an alternate reality in which some of their biggest decisions never came to pass. The official synopsis for the episode reads: “With the ugly truth behind Frankie’s assassination revealed, a torn Olivia wonders how different her life – and the country – would be if she, Mellie and Cyrus had never rigged Fitz’s election.” The episode comes at just about the midway point for Season 6, which was pushed to midseason this year after Washington became pregnant with her second child.

“Mystery Science Theater 3000,” Netflix, Friday

The series about a man and two robot sidekicks cracking wise on a cheesy B-movie returns to television for the first time in almost 20 years this week. Original series creator Joel Hodgdon launched a record-breaking Kickstarter campaign to create a new season of the cult classic, with the new installment starring Jonah Ray, Baron Vaughn, Hampton Yount, Felicia Day, and Patton Oswalt among others. The season was originally supposed to consist of 12 episodes, but the Kickstarter campaign was so successful that the team instead made 14 episodes, including a Christmas special.

Guerrilla, HBO, Sunday, 9 p.m. (CRITICS’ PICK)

At first blush, Showtime’s debut event series “Guerrilla” resembles a standalone potboiler, reminiscent of well-drawn spy stories like the many excellent adaptations of John Le Carré novels. It has that gloss of period romance — whether that is nightclubs filled with cigarette smoke, where shadowy figures come to deal and dance; or the quaint tools of pre-Internet revolution — typewriters, communiqués, the odd persistence of the rotary phone. Stories like this always play a little with that inherent dramatic irony of the period piece — where the audience knows, in broad sketches, what the world will become, but the characters still don’t. Except “Guerrilla” doesn’t revolve around a mystery, where a secret is buried somewhere and must be found. It is not a story about discovering, but rather about becoming; the mystery, if there is one, is how it happens that militants, once so much like everyone else, come to the point where they choose infamy and violence. (Read the full review here)

The Leftovers, HBO, Sunday, 9 p.m. 

The series about the mysterious disappearance of 2% of the global population and those who were left behind will begin its third and final season this week. The Justin Theroux-led drama took place in New York for Season 1, while Season 2 moved things to Texas. In Season 3, the cast will start off in Texas but eventually migrate to Australia, where Theroux’s Kevin will look to reunite with his father.

Girls, HBO, Sunday, 10 p.m. 

Lena Dunham’s Emmy- and Golden Globe-winning series will end this week after six seasons. The show has spurred heated conversations about millennials, women, pushed boundaries of sex on television and reaped heaps of critical praise, and strong criticism. “I just love how women approach me and say it has helped them feel more comfortable in their bodies or leave a challenging relationship,” Dunham said in February. “Even men come up to us and say it helped them understand their daughters or wives. If we can make those human connections with our work, then I don’t think there is anything better.”