Recycled Heartbeats

In the droll, boring life of a party boy, Marshall Lee finds excitement and peace in working at his public library. The work clears his muddled mind, as he says. Sound a tad bit boring? Well even there, among the silence and towers of books, he rediscovers the thrill of life he was missing for so long. Bubbline & Marblegum/Gumlee (idk exact ship name?). Multi-chap prompt-fic. AU