“Grey's Anatomy” season 15 premiered last week with two back-to-back episodes watched by nearly 7 million viewers, a remarkable feat for a show that has outlasted two presidential administrations, one of my marriages, two of my cats and declining broadcast viewership. This week, with the Grey Sloan Memorial crew firmly re-established at 8 p.m., ABC has brought back its spinoff “Station 19” for the 9 p.m. hour. Slotted comfortably between its parent show and Shondaland's other hit, “How To Get Away With Murder,” the second season of the firehouse drama is staying even closer to home than its first iteration.

There's a reason for this. Creator Shonda Rhimes has been one of broadcast’s most successful TV producers in this century, not only in terms of ratings, but brand loyalty. (The success of her website, Shondaland.com, speaks to how her fans will apparently follow her anywhere.) Her shows are tied closely to her personal brand, and her name is dropped copiously in series marketing.

But with "Station 19," Rhimes is doing something that is a little experimental — although still in keeping with her and ABC's broader strategy. “Station 19,” which takes over the time slot recently abandoned by her series “Scandal,” is clearly designed to make sure ABC’s Shondaland block of programming on Thursday nights stays as secure as possible, and that fans stick around for multiple shows each week. This is particularly important given the rumors that “Grey’s Anatomy” will be ending its historic run soon.

Unlike most spin-off series, “Station 19” does not take a popular character and move them far away to a new home. Rhimes has done that before with her first “Grey’s Anatomy” spin-off “Private Practice.” This time, she’s taking popular ”Grey’s” character Ben Warren (played by Jason George) and moving him… absolutely nowhere. He still lives in the same town. He remains married to the same leading character on “Grey's Anatomy,” Miranda Bailey (played by Chandra Wilson, one of only four of the original cast to have lasted for all 15 seasons and counting.) He just changes jobs, from doctor to firefighter. His place of employment moved (as the launch trailer boasted) all of three blocks down the street. His old co-workers at Grey Sloan are still people he works closely with as a first responder, just in a different capacity. Welcome to “Grey's Anatomy: Pyrotechnics.”

In most cases, a spin-off show hooks viewers in with nostalgia but quickly tries to establish its own unique brand. And for most of the ten-episode first season, “Station 19” did just that. But the season two premiere suggests showrunners are retreating back to the safety of a Grey Sloan hospital setting, with characters from the two shows heavily interacting, both professionally and romantically.

The obvious goal here is to hold over every last viewer from the 8 p.m. slot, as well as start mixing the brands and their casts.

As with most everything Rhimes does, this is no accident. ABC has said the crossovers between the two series will come hot and heavy this year. During the May upfronts, ABC’s Entertainment president Channing Dungey stated that the network and Rhimes were looking at “more dynamic interplay” between the two series. “Station 19” doesn’t quite have the numbers of “Grey’s Anatomy,” but its launch was respectable, with the first season maintaining a five million-a-week viewer average. The obvious goal here is to hold over every last viewer from the 8 p.m. slot, as well as start mixing the brands and their casts.

Although it feels like a TV staple, “Grey’s Anatomy” cannot run forever. There was a time not so long ago when the show ending would not have been a significant problem for ABC. But in August of last year, Rhimes stunned the broadcast world by announcing she would be jumping to Netflix and allowing her deal with ABC to expire in June of this year. Any shows currently airing on ABC would continue, but her time creating new ones for the network is over. That means making sure shows like “Station 19” thrive is now imperative for ABC if they want to keep their corner of Shondaland going.

When “Grey’s Anatomy” was renewed for seasons 15 and 16 last spring, lead actress Ellen Pompeo revealed that she had discussed it with Rhimes, and the show would continue as long as Pompeo was happy playing titular character Meredith Grey. When the 16th season starts next year, the series will break the record for longest running medical drama on American television. (It is currently tied with “ER,” which was canceled after season 15.) Rumors are now swirling that Pompeo is considering calling it a day when season 16 ends, though nothing official has been announced and most likely will not be for another year.

Still, if Rhimes is serious about not continuing “Grey’s Anatomy” without Pompeo (and ABC agrees), prepping “Station 19” to move down to 8 p.m. and take over the primetime slot on Thursdays would likely be the preferred move for all involved.

ABC is not the only one invested in keeping Shondaland going, however. Rhimes announced she has no less than eight shows in various stages of development at Netflix. But it will be a while before any of them are finished, with nothing new to come until at least 2019, if not 2020. Having multiple hit shows running at once is part of Rhimes’ successful brand. And as long as she still has a couple of hits on broadcast, she can weather a flop or two on Netflix as she finds her footing.