What's Worth Watching: Maron, Law & Order: SVU, Underground and more for Wednesday, May 4

Maron (9/8c, IFC): A crossover episode I'd like to see: Marc Maron popping into Mom's AA support group. The fourth season of this Louie-like slice of a downtrodden comedian/podcaster's life goes beyond dark comedy to the realm of suicide watch, as Maron's curmudgeonly alter ego has sunk somewhere below rock bottom in his painkiller addiction. Now living in a storage locker—don't ask about sanitation—and relentlessly texting old pal Louis C.K. (who isn't returning) in hopes of jumpstarting his dormant career, Oxy-popping Maron heads to rehab in the second of two back-to-back episodes, and the sailing is about as smooth as you'd expect. "Depression? Anxiety?" asks a doctor trying to diagnose this wretch. "Yea, probably, I'm a Jew," he quips. The only proper response to these episodes: Oy.

Law & Order: Special Victims Unit (9/8c, NBC): Look who's back on the job: Richard Belzer as lovably cynical Detective John Munch. He may have retired two seasons ago, but the veteran of SVU and Baltimore-set Homicide: Life on the Street is called back to duty when a suspect from one of his previous cases is once again accused of rape.

Underground (WGN America, 10/9c): Only one more week before the season finale of this hit historical drama, and it's all about rescuing Rosalee (Jurnee Smollett-Bell) from August (Christopher Meloni). While Cato (Alano Miller) and Noah (Aldis Hodge) plot an escape plan, Rosalee has her own ideas, with nail-biting consequences.

Inside Wednesday TV: Mother's Day never goes well on ABC's The Middle (8/7c), which is why Frankie (Patricia Heaton) decides to give the family a pass this year—as long as they "pay it forward" with good deeds to each other. But you know what they say about the best-laid plans in the Heck household. … Things aren't much rosier on The Goldbergs (8:30/7:30c, ABC), when Barry (Troy Gentile) and Erica (Hayley Orrantia) forget to get Beverly (Wendi McLendon-Covey) a gift, and Mom decides to cash in each and every one of their off-the-cuff "Mom Coupons." … If your family is into lighthouses the way mine is, you'll want to tune into PBS's Nova for Operation Lighthouse Rescue (9/8c, check local listings at pbs.org), which follows engineers as they attempt to save the historic Gay Head Lighthouse perched on the eroding cliffs of Martha's Vineyard.