Three weeks in December

This novel interweaves the perspectives of Jeremy, an engineer who leaves small-town Maine in 1899 to oversee the construction of a railroad across East Africa, and finds himself the reluctant hunter of two lions killing his men in nightly attacks; and Max, an American ethnobotanist who travels to Rwanda in 2000 in search of an obscure vine that could become a lifesaving pharmaceutical, but finds herself shadowing a family of gorillas whose survival is threatened by a violent rebel group from nearby Congo.