from Sara Gruen's web site:
As a young man, Jacob Jankowski was tossed by fate onto a rickety train that was home to the Benzini Brothers Most Spectacular Show on Earth. It was the early part of the great Depression, and for Jacob, now ninety, the circus world he remembers was both his salvation and a living hell. A veterinary student just shy of a degree, he was put in charge of caring for the circus menagerie.
It was there that he met Marlena, the beautiful equestrian star married to August, the charismatic but twisted animal trainer. And he met Rosie, an untrainable elephant who was the great gray hope for this third-rate traveling show. The bond that grew among this unlikely trio was one of love and trust, and, ultimately, it was their only hope for survival.
The story is told from Jacob's point of view as a series of flashbacks. Jacob is in his 90's and struggling to maintain a semblance of independence in a nursing home, and he remembers his early years working at a circus. I found this book fascinating. There's a reading guide here.