TV THIS WEEK: Watchmen, Arrow, Treadstone premieres; The Simpsons Treehouse of Horror

It's a big week for premieres and Halloween specials. There are plenty of biggies, but few bigger than the beginning of the end for Arrow.

The flagship CW superhero series begins its final season this week, with a shortened run set to culminate with the Crisis on Infinite Earths crossover event. HBO is also debuting its Watchmen adaptation this week, which aims to pick up in the present day after the events of the original comic. If you're looking for action, USA's Jason Bourne spinoff series Treadstone should likely fit the bill.

Digging a bit deeper, SYFY is debuting the film Critters Attack!, and Fox has the premiere of its latest Simpsons Halloween special with "Treehouse of Horror XXX." USA also has the season two premiere of its small screen take on the Purge horror franchise. Beyond that, there's still plenty more to watch. There's new The Flash, The Terror, Black Lightning, Nancy Drew, American Horror Story, The Walking Dead and more.

Check out the full rundown below and let us know what you'll be watching.


HIGHLIGHTS

Arrow (The CW), Tuesday 9PM - "Starling City"

SEASON PREMIERE: The Season 7 premiere: Oliver returns to Starling City, where he encounters familiar faces while trying to decipher the Monitor's mission. Meanwhile, Mia and William's team clash with a new foe.

Treadstone (USA), Tuesday 10PM - "The Cicada Protocol"

SERIES PREMIERE: From the world of Jason Bourne, agents across the globe are "awakening" to resume deadly missions.

Critters Attack! (SYFY), Saturday 9PM

PREMIERE: A baby sitter takes kids on a hike, unaware an alien ship full of hungry critters has crash landed nearby.

The Simpsons (Fox), Sunday 8PM - "Treehouse of Horror XXX"

Milhouse is trapped in another dimension; dead Homer's spirit tries some new bodies on for size; Selma finds love in an unlikely place.

Watchmen (HBO), Sunday 9PM - "It's Summer and We're Running Out of Ice"

SERIES PREMIERE: In an alternate history, superheroes are treated as outlaws.

MONDAY

Black Lightning (The CW), Monday 9PM - "The Book of Occupation: Chapter Two"

With Freeland under full-blown occupation, the Pierce family gets pulled in different directions. Jefferson and Lynn find themselves at odds with each other. Meanwhile, Anissa rebels as Blackbird while Jennifer feels powerless despite having powers.

The Terror (AMC), Monday 9PM - "Infamy: Into the Afterlife"

Henry and Asako look to the past to provide answers to their current turmoil. Chester and Luz grapple with their identities in hopes of saving those who are dearest to them. Amy and Yamato-san struggle to once again assimilate into American life.

Lodge 49 (AMC), Monday 10:10PM - "The Door"

After the events of Mexico, the Lynx regroup and prepare for an important coronation.

TUESDAY

The Flash (The CW), Tuesday 8PM - "A Flash of the Lightning"

Faced with the news of his impending death, Barry's resiliency suffers as he struggles to fight fate. Meanwhile, Cecile's career as a D.A. conflicts with her identity when she crosses paths with a villainous meta-human.

Arrow (The CW), Tuesday 9PM - "Starling City"

See more in our "Highlights" section above.

The Purge (USA), Tuesday 9PM - "This Is Not a Test"

SEASON PREMIERE: Four interconnected characters navigate the aftermath of the Purge over the ensuing year.

Emergence (ABC), Tuesday 10PM - "No Outlet"

After learning more about Piper's origins, Jo struggles with the decision to shelter her. Benny enlists a friend to hack Kindred's secret files, and Chris clashes with a headstrong informant he's assigned to protect.

Treadstone (USA), Tuesday 10PM - "The Cicada Protocol"

See more in our "Highlights" section above.

WEDNESDAY

Riverdale (The CW), Wednesday 8PM - "Chapter Fifty-Nine: Fast Times at Riverdale High"

Archie encourages Mad Dog to attend Riverdale High and join the football team. Jughead meets Mr. Chipping, who offers him a spot at an elite school called Stonewall Prep. Veronica is conflicted when information about her involvement in Hiram's arrest leaks to the public. Kevin applies for a spot on the Blue & Gold to make amends with Betty. And Cheryl goes head to head with Mr. Honey, the school's new principal.

Nancy Drew (The CW), Wednesday 9PM - "The Secret of the Old Morgue"

Nancy learns that Tiffany Hudson's corpse is being moved out of Horseshoe Bay for a private autopsy, which spurs her to attempt one of her most risky missions yet. Meanwhile, Bess and Ace enlist the help of a stranger in an attempt to help Nancy. Lastly, the town gathers to participate in the annual bucket ritual done on the last night of the Summer Festival.

American Horror Story: 1984 (FX), Wednesday 10PM - "Red Dawn"

As twilight broaches, the survivors brace for a final brawl.

THURSDAY

Supernatural (The CW), Thursday 8PM - "Raising Hell"

Sam, Dean and Castiel call on Rowena to help keep the evil souls at bay and get an unexpected assist from Ketch.

Legacies (The CW), Thursday 9PM - "This Year Will Be Different"

Hope's latest hunt leads her on a collision course with the past she's been trying to leave behind. Meanwhile, on their first day back in school, Landon's newfound status as the popular guy leads to tensions with Josie. Elsewhere, as MG contemplates telling Lizzie how he feels about her, the arrival of a mysterious vampire puts a wrench into his plan. Finally, as Alaric gets settled into his new role at Mystic Falls High School, the students of the Salvatore School meet their new headmaster.

The Good Place (NBC), Thursday 9PM - "Tinker, Tailor, Demon, Spy"

Uncertainty abounds when an unexpected visitor arrives.

Evil (CBS), Thursday 10PM - "Rose390"

Kristen, Ben and David are hired to evaluate Eric, a seemingly psychopathic 9-year-old boy. Eric takes a liking to David, which leaves them hopeful they can curb his violent behavior. Also, Kristen is most affected by this investigation as she worries about her young daughters who lied about a horror game their grandmother, Sheryl, bought behind her back.

FRIDAY

Charmed (The CW), Friday 8PM - "Things to Do in Seattle When You're Dead"

The Charmed Ones must learn to navigate the new world they now inhabit. Macy tries making sense of some very intense dreams and Mel and Maggie try to accept their new roles. Harry isn't quite himself ever since his encounter with the hooded villain, forcing him and Mel to go on an old-fashioned road trip in search of the demons attempting to bring about the extinction of all witches. A personal loss strengthens the bond between Maggie and Mel.

Van Helsing (SYFY), Friday 10PM - "Broken Promises"

After an epic battle, Axel reconciles with Vanessa and comes to terms with the death of Scarlett.

SATURDAY

The Mummy (FX), Saturday 7PM

A battle in the Middle East accidentally unearths Ahmanet, a betrayed Egyptian princess who was entombed under the desert. Now, a soldier of fortune must stop the resurrected monster as she embarks on a furious rampage through London.

Glass (HBO), Saturday 8PM

PREMIERE: David Dunn looks to deliver vigilante justice to the Beast -- the madman who has superhuman strength and 23 personalities. Their epic showdown leads them to the mysterious Elijah Price, the criminal mastermind who holds critical secrets for both men.

In Search Of (History), Saturday 8PM - "Secrets Unearthed"

An in-depth look into unexplained phenomena from all over the world.

Critters Attack! (SYFY), Saturday 9PM

See more in our "Highlights" section above.

SUNDAY

God Friended Me (CBS), Sunday 8PM - "All Those Yesterdays"

Miles, Cara and Rakesh support Joy when the God account sends her a friend suggestion that brings up painful memories for her; Arthur is tempted by a professional opportunity.

The Simpsons (Fox), Sunday 8PM - "Treehouse of Horror XXX"

See more in our "Highlights" section above.

Batwoman (The CW), Sunday 8PM - "Down Down Down"

The city waits for another visit from who they think is Batman; Alice continues to taunt Kate; Mary gets an unexpected new friend; as Batwoman faces a new enemy, Kate realizes she must make a decision.

Supergirl (The CW), Sunday 9PM - "Blurred Lines"

Kara tries to mend her relationship with Lena; J'onn J'onzz goes deep into his memories; Kelly tries to help an old friend.

Family Guy (Fox), Sunday 9:30PM - "Disney's The Reboot"

After the network decides it is time to reboot the series, three versions of the reboot are shown to a focus group, which produces some surprising feedback.

The Walking Dead (AMC), Sunday 9PM - "Ghosts"

The threat of the Whisperers return leads to paranoia sweeping over Alexandria; in the meantime, Carol battles with the need for revenge.

Watchmen (HBO), Sunday 9PM - "It's Summer and We're Running Out of Ice"

See more in our "Highlights" section above.

Mr. Robot (USA), Sunday 10PM - "403 Forbidden"

Whiterose has the feels; Elliot gets owned by his own hack; an old foe waits.

*TV listings via TV Guide, Zap2it.