Provocative, gripping, startling: bestselling author Ben Bova delivers a knockout read with his trademark blend of cutting edge science and unrelenting suspense...

Some see stem-cell research as mankind's greatest scientific breakthrough. Others see a blasphemous attempt to play God. Suddenly, the possibility of immortality exists. Two brothers, both doctors, stand on opposite sides of the controversy. To Dr. Arthur Marshak, his work is a momentous gift to humanity. To Dr. Jessie Marshak, it is a curse. Between them stands a beautiful, remarkable woman both brothers will do anything to save.

Somehow, before it's too late, Arthur and Jessie Marshak must bridge the gap that divides them - on an issue that could mean nothing less than life or death for millions.