Thomas discovers mysteries of the past and must help a new friend, save a ruined castle and may even find some treasure when Sir Robert Norramby comes to the Island of Sodor.
| Actor | Role |
|---|---|
 Mark MoraghanNarrator (voice) | Narrator (voice) |
 Ben SmallThomas / Toby / Rheneas / Troublesome Trucks (voice) | Thomas / Toby / Rheneas / Troublesome Trucks (voice) |
 Keith WickhamEdward / Henry / Gordon / James / Percy / Skarloey / The Fat Controller (voice) | Edward / Henry / Gordon / James / Percy / Skarloey / The Fat Controller (voice) |
 Teresa GallagherEmily / Belle / Annie / Clarabel (voice) | Emily / Belle / Annie / Clarabel (voice) |
| MMatt WilkinsonSpencer / Cranky / Kevin (voice) | Spencer / Cranky / Kevin (voice) |
 Togo IgawaHiro (voice) | Hiro (voice) |
| BBob GoldingStephen (voice) | Stephen (voice) |
 Jonathan ForbesConnor (voice) | Connor (voice) |
 Rebecca O'MaraCaitlin (voice) | Caitlin (voice) |
 Kerry ShaleDiesel (voice) | Diesel (voice) |
 Steven KynmanPaxton / Jack (voice) | Paxton / Jack (voice) |
 David BedellaVictor (voice) | Victor (voice) |
 Michael LeggeLuke (voice) | Luke (voice) |
 Miranda RaisonMillie (voice) | Millie (voice) |
 Mike GradySir Robert Norramby (voice) | Sir Robert Norramby (voice) |