Seeing things

"Birdie Wainwright sees things--purple flowers growing out of floors and alpine slopes where her stairs ought to be. But she's not worried. It's just her macular degeneration acting up. No vision is going to stop this tango-loving grandmother!...Then one day, she sidesteps an imaginary boulder---and tumbles down the stairs. The bad news? A broken ankle. The worse news? She must convalesce at her son's home, under the harsh eye of her daughter-in-law. And that's when Birdie's visions really take flight!...For there in her room, bold as brass, sits the legendary Huck Finn..."--p.[4] of cover.