In the Swiss Alps, Lady Penelope and Tin-Tin go undercover to investigate the link between a popular cabaret band's performances and mysterious attacks on military aircraft.
| Actor | Role |
|---|---|
 Sylvia AndersonLady Penelope Creighton-Ward (voice) | Lady Penelope Creighton-Ward (voice) |
 David GrahamBrains / Parker / Olsen / Captain Savidge / Hitchins (voice) | Brains / Parker / Olsen / Captain Savidge / Hitchins (voice) |
 Peter DyneleyJeff Tracy (voice) | Jeff Tracy (voice) |
 Shane RimmerScott Tracy (voice) | Scott Tracy (voice) |
 David HollidayVirgil Tracy (voice) | Virgil Tracy (voice) |
 Matt ZimmermanAlan Tracy / Banino / Macklin / Foreign Lieutenant (voice) | Alan Tracy / Banino / Macklin / Foreign Lieutenant (voice) |
 Ray BarrettJohn Tracy / Cass Carnaby / Commander, Matthews Field / Radio Maxwell DJ (voice) | John Tracy / Cass Carnaby / Commander, Matthews Field / Radio Maxwell DJ (voice) |
 Christine FinnTin-Tin Kyrano / Grandma Tracy (voice) | Tin-Tin Kyrano / Grandma Tracy (voice) |
| JJohn TateMaxie / Scheiler / Foreign Colonel (voice) (uncredited) | Maxie / Scheiler / Foreign Colonel (voice) (uncredited) |