The song was written and sung by Dennis DeYoung. The track is a mid-tempo ballad about one who breaks up with a lover and pleads to get the person back. The song reached #6 on the U.S. Billboard Hot 100 in June 1983 and #56 in the UK Singles Chart. It also reached #15 on the Canadian RPM Top Singles chart the week of July 2, 1983. At the time, it was the seventh Styx single to peak in the top 10 of the Billboard Hot 100.

According to Dennis DeYoung in a 2005 interview with classicrockrevisited.com, the track was originally slated as the first single from Kilroy Was Here until the staff at A&M suggested "Mr. Roboto".

The video of the track was directed by Brian Gibson. It starts out with Dennis portraying Kilroy looking at a picture of a girlfriend he lost (the picture is of Dennis' wife in real life Suzanne) and then gets up to go in another room which changes into the prison that his character of Kilroy was in. Then Dennis changes into the Kilroy as prisoner character and joins the members of Styx who play prisoners in the video performing the track and then the end shows Dennis as he appeared at the intro.

The reprise of the track was more to do with not letting rock and roll die and had a teaser of the riff to "Mr. Roboto" before ending like a 50s rocker with Tommy Shaw singing the first section and DeYoung the finale. The live version ends with the ending guitar chords from "Twist and Shout."

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Wikipedia