The episode was seen by an estimated 2.37 million household viewers and gained a 1.1/3 ratings share among adults aged 18–49, according to Nielsen Media Research.
Noting that Captain Holt (Andre Braugher) feels lonely while Kevin is in Paris on sabbatical, Jake (Andy Samberg) decides to cheer him up by suggesting they take on the cold case of a criminal that was left on his desk.
However, his leadership is jeopardized due to the stubbornness of Hitchcock (Dirk Blocker) and Scully (Joel McKinnon Miller), who refuse to work after Terry took their sandwich and the fact he destroyed Holt's office by angrily shutting the door.
Rosa (Stephanie Beatriz) attempts to get him to move on so they can work on a case, even going out of her way to get him a new one named Arlo, but Boyle refutes her advances and coldhearted approach.
After Rosa ends up adopting Arlo, she understands how important Jason was to Boyle and organizes a proper funeral to help him grieve.
In its original American broadcast, "9 Days" was seen by an estimated 2.37 million household viewers and gained a 1.1/3 ratings share among adults aged 18–49, according to Nielsen Media Research.
"[3] Conversely, Allie Pape from Vulture gave the show a perfect 5 star rating out of 5 and wrote, "It's a rarity that Brooklyn Nine-Nine can score a hat trick by balancing its hefty cast into equally compelling B- and C-plots, but this week was an exception.