What to Watch Thursday: Wade’s Raleigh-to-Asheville romance suffers on ‘The Unicorn’

The Unicorn (9:30 p.m., CBS) - When Wade and Shannon have trouble connecting — with him in Raleigh and her in Asheville — Wade is forced to consider the realistic future of their relationship. Meanwhile, Forrest starts suffering from insomnia and doesn’t know how to tell Delia that she is the reason.

Dateline NBC (10 p.m., NBC) - In this repeat, Andrea Canning reports on the Heather Elvis case, interviewing the parents of the South Carolina woman who disappeared from Myrtle Beach in 2013. Also included is an interview with Tammy Moorer, the woman found guilty of kidnapping Elvis (it was her first interview after her conviction). “Dateline” first reported this story for their “Missing in America” digital series, shortly after Elvis vanished. She remains missing. (Note: “20/20” airs a special on Heather Elvis on Friday.)

Mr. Mercedes (Peacock) - Author Stephen King says this third season of his adapted “Mr. Mercedes” / “Bill Hodges” trilogy is “the best one.” In Season 3, beloved local author John Rothstein is found murdered, and Hodges, Holly, and Jerome, along with local police, must track down his killer.

Persona: The Dark Truth Behind Personality Tests (HBO Max) - This HBO documentary explores the unexpected origin story of America’s great obsession with personality testing, uncovering the intriguing history behind the world-famous Myers-Briggs Type Indicator, while raising ethical questions and demonstrating how some personality tests may do more harm than good – like impacting online dating matches or job prospects. This eye-opening documentary reveals the profound ways that ideas about personality have shaped our society.

Walrus and the Whistleblower (discovery+) - Directed by Nathalie Bibeau, this documentary tells the story of Phil Demers, a trainer at Niagara Falls’ Marineland who was famous for his bond with Smooshi the walrus. But Demers suddenly quit his dream job after a decade and made claims of animal abuse, waging a war on social media. For the next decade, Demers is embroiled in a stranger-than-fiction public campaign to Save Smooshi, becoming trapped in his own story and swallowed whole by his crusade.

Some programming descriptions are provided by networks.