The second episode takes the kids back in time to England during World War II where they meet Dr. Charles Drew who developed large-scale blood banks for victims of the war.   We learn about the blood stream, blood cells and the challenges Dr. Drew faced. We even see the Timeship transform into miniature mode and enter the blood stream.   Meanwhile, back in present-day U.S., Manny and Kwame are cooking up a heartbeat experiment at school that parallels the lessons about Dr. Charles Drew. All this happens as Nia and crew face off again with the evil Komo as they get closer to rescuing her parents.