As pilot Wallis is forced out of the RAF due to a health disorder, he falls back on his skills as a musician and joins the big band circuit, where he encounters womanizing private detective Trapp.
As the band set to replace their singer, the two boys become involved in a plot to bring down a murderous Scottish gangster.
As Eddie continually tries to win Dolly's love, Eric's detective work unearths a massive scam.