Picture this: Meryl Streep, struggling actor. 

I know, it’s too far-fetched to believe. But that’s the character the Oscar-winning actress plays in Season 3 of Hulu’s “Only Murders in the Building,” and she brings a surprising sense of whimsy to the popular series, now in its third season.

The show needed her: The slapstick shtick of “Only Murders” (new episodes Tuesdays, ★★½ out of four) is in danger of getting old. Steve Martin, Martin Short and Selena Gomez make an uncannily beguiling trio, but the formula of quirky murder-solving in an aesthetically pleasing Upper West Side Manhattan apartment building needs to be rejuvenated.

How many murders can there be in one building, do you ask? Well, at least three, so far. They’ll need yet more gimmicks, A-list cameos and musical numbers to make a fourth murder work. 

Season 3 of the mystery comedy finds our podcasting team ‒ Charles (Martin), Oliver (Short) and Mabel (Gomez) ‒ confronted with the latest death, which was teased in the Season 2 finale: Ben Glenroy (Paul Rudd), a movie star who just happened to be the lead in has-been theater director Oliver’s big comeback play on Broadway, in which Charles also stars.

As in previous seasons, the trio is intimately connected to Ben’s death, and surrounded by a quirky supporting cast full of red herrings and murder suspects. Streep’s Loretta stands out as immediately suspicious, a manic and flighty woman who was getting her big break (and a date) from Oliver. “Grey’s Anatomy” star Jesse Williams also shows up as a new love interest for Mabel, a documentarian with the almost-too-twee name “Tobert.” 

The mystery itself is sometimes lukewarm on intrigue. The writers occasionally struggle to balance the whodunnit of it all with the overarching character stories, as Oliver clings to his dying career, Charles gets serious with girlfriend Joy (Andrea Martin) and Mabel faces her unaccomplished adulthood. It’s as though they’re not sure which aspect of the show is more appealing to the audience, so scenes dramatically swing back and forth in tone and format, from fever-dream fantasies to supernatural ghost hunts to full-on Broadway showstoppers. It’s all entertaining in sum, but doesn’t always fit together as you’re watching each episode. 

How to watch it: :When does 'Only Murders in the Building' Season 3 come out? Release date, cast, trailer

It’s fun to see Streep, the grand dame of American acting, as a harried and humble Broadway wannabe who never made it in acting but never stopped trying. And it’s equally delightful to imagine nice-guy Rudd as a pompous Hollywood jerk known for his role as “CoBro,” a snake who fights crime (the series gets a lot of mileage out of that joke). That’s always been part of the draw of “Only Murders” − the idea that we’re watching these likable stars just goof around with each other.  Like Oliver, the series is fond of name-dropping celebrities and using unlikely cameos as an engine of storytelling (and yes, there are more). In other series it might come across as crass or hacky. Here it’s charming (for now). 

A series cannot ride only on star-powered charisma forever. After Streep, what bigger star can you get?