A fantastical tale about a slightly batty amateur magician, Frank and his inquisitive 10-year-old grandson, Mike, who dicovers the foot of a rainbow in a railroad siding. Mike's school chums are initially skeptical but later join him in building equipment to calculate where the next rainbow will tou

A fantastical tale about a slightly batty amateur magician, Frank and his inquisitive 10-year-old grandson, Mike, who dicovers the foot of a rainbow in a railroad siding. Mike's school chums are initially skeptical but later join him in building equipment to calculate where the next rainbow will touch down. When one appears, the trio, along with Mike's older brother Steven, pedal off as they are swept up into the sky--in search of the end of their rainbow.