Henry, Jessie, Violet, and Benny are off to college!. . . that is, they are off to help Grandfather at a convention of young astronomer students at Mountvale College. The children are excited and fascinated by what they can learn about astronomy, but when valuable information and one of the students go missing, the kids know that there is a mystery brewing. Can the Boxcar Children find the student and the information before it's too late? Number #59 in the series.