After discovering a young boy aboard Thunderbird 2, Jeff tries to decide how to deal with the stowaway while his sons break protocol by enthralling him with tales of their past adventures.
| Actor | Role |
|---|---|
 Shane RimmerScott Tracy (voice) | Scott Tracy (voice) |
 David HollidayVirgil Tracy (voice) | Virgil Tracy (voice) |
 Matt ZimmermanAlan Tracy (voice) | Alan Tracy (voice) |
 David GrahamGordon Tracy / Brains / Morrison / Bob Gray / Solarnaut Asher / Captain Hanson / Frank / Dave Clayton (voice) | Gordon Tracy / Brains / Morrison / Bob Gray / Solarnaut Asher / Captain Hanson / Frank / Dave Clayton (voice) |
 Ray BarrettEddie Houseman / J.B. Lester / Colonel Harris / Fireflash Co-Pilot / Assistant Controller / Bridge Controller (voice) | Eddie Houseman / J.B. Lester / Colonel Harris / Fireflash Co-Pilot / Assistant Controller / Bridge Controller (voice) |
 Sylvia AndersonChip Morrison / Lady Penelope Creighton-Ward (voice) | Chip Morrison / Lady Penelope Creighton-Ward (voice) |
 Christine FinnTin-Tin Kyrano (voice) | Tin-Tin Kyrano (voice) |
| JJohn TateSolarnaut Camp (voice) (uncredited) | Solarnaut Camp (voice) (uncredited) |