mordicai gerstein (november 24, 1935 – september 24, 2019) was an american artist, writer, and movie director. he was best known for illustrating and writing children's books. he illustrated the comic mystery fiction series "something queer is going on". he directed the nbc television movie "the berenstain bears' christmas tree". he won the 2004 caldecott medal for u.s. picture book illustration, recognizing "the man who walked between the towers", which he also wrote. he was born in los angeles, california.