At the end of the flashback in Along Came December, we return to the present, where things have gone to shit. Mordecai's lost her job, her friends, and most of her desire to live. She'd been so obsessed with Carl's trial, and ever since she fucked that up, she doesn't know what she's living for anymore. As much as she'd like to curl up and die, the last case Mordecai worked before she was fired isn't finished with her yet, and her roommate/best friend's life is on the line. She needs to pull herself together in order to figure out what's going on before she loses the last of what she loves.
Nightshift, by the Commodores
This is actually a Presley song, Presley being Mordecai's roommate and best friend. He's a former prostitute currently working as a stripper for a man of questionable intentions. Presley's keeping a few secrets of his own, plus he's trying to keep his boyfriend safe. He's up to his neck in trouble, and the one person who could help him is too busy wallowing in grief and self-pity to do anything about it. Presley's run out of cards to play, and without Mordecai's help, he'll stay caught in a dangerous web.
Happy Little Pill, by Troye Sivan
Also a Presley song. It might perhaps have something to do with why he's in trouble.
Just Breathe, by Pearl Jam
Another Presley song, although this one's from Mordecai's perspective. Bad things have happened and Presley's down, and Mordecai's panic is overwhelming her as she flashes between watching Max die in her memory and watching Presley die right now. She wants to save him. She's desperate to save him. She's doesn't know if she can save him.
Give Me Love, by Ed Sheeran
This is a Paddy song, Paddy being Mordecai's ex-partner and the guy who's kept her going since Max died. Paddy's furious with her for what she did at Carl's trial, and he's had nothing to do with her since. But when the shit goes down and she calls him for help, he's going to be there for her. Just maybe not in time.
Stay tuned for the fourth and final part!