What I'm pretty sure Suzanne Collins had in mind for Plutarch's backstory.
President Snow sighed heavily. The recent unrest in the districts had placed its toll on him. He needed something to refresh his spirits. He reached for the telephone.
"Plutarch? I have grown tired of repressing the districts. I feel the need to get my groove on!"
Plutarch rolled his eyes. It was 3AM and he was expected to come and disco with Snow. Ah, the things he did for power. "President, with all due respect, I think my faculties would be more effectively utilized if I were planning the Hunger Games."
"Plutarch! You're my only friend! You're my BFFAEAEAEAEAEAE! You can't split on me bro!" Plutarch felt a deep rage inside him, thinking how great it would be if there were a rebellion against Snow.
"Fine, I'll be right over." Snow giddily put on his white jumpsuit. He peeked out his curtains toward his front door, waiting for Plutarch to arrive. When a car pulled into his driveway, Snow almost flew down the door to let Plutarch in. He was happy to see Plutarch had put on a matching white jumpsuit, as per usual.
Snow led him to a bookcase, where he pulled out a book and opened a secret door. The pair walked through into the secret presidential dance floor. Plutarch started forming plans of revenge. As the two danced for hours, Plutarch's plans for rebellion became more specific and planned out. When he left the manor, there was no doubt in his mind what he had to do.
Although I realize it'd be hard to drop a backstory scene in Mockingjay Part 2 with Phillip Seymour Hoffman dead, if the producers were to put this scene in, I want them to know I would turn a blind eye.