9-1-1 has gotten back into business after sending a few responders to Austin. The closely-guarded secret between Maddie and the Buckley parents got a little less closely-guarded when she shared it with Chimney (much to his dismay), and then it finally got out to Buck in the final moments of the episode.
The 9-1-1, What’s Your Grievance? Was a heartbreaking episode for Buck even if he was not completely aware of how much he had been wronged by people. At the end of the hour, he was going through Maddie’s baby box that her parents had kept for her (but clearly hadn’t kept one for Buck), and discovered a picture of a young boy, which he initially took as a photo of himself… until he saw that the photo was dated 1988, which was before he was born. Maddie was finally forced to drop the bombshell: the boy in the picture was Daniel, their brother who died, seemingly before Buck was born.
Buck was adopted and that was the big secret. It does make sense as there is a lot of age difference between Maddie and Buck and that was a huge secret kept from him his entire childhood. Still, the Buckley parents having what might have been an accidental third child after losing their second could make a lot of sense in explaining why they weren’t as invested in Evan, considering the personalities they displayed in this episode.
The next episode called “Buck Begins” will feature this: “The 118 race to save the lives of workers trapped in a five-alarm factory fire. Meanwhile, Maddie reveals a painful family secret that causes Buck to confront his childhood and answer why he is the daredevil he is today.”