Host Mo Rocca shows us the underwater drone bringing bait to the fish; the inventor of 3D printing; updates on past innovators; and, how railroad signals changed train traffic.

Host Mo Rocca shows us the fireless grill that cooks using heat from the sun; the sponge that can sop up ocean oil spills; the scuba diving tank you can pump up by hand; and, the innovator whose "car of tomorrow" failed to catch on.