Mr. Conductor's supply of magic gold dust, which allows him to travel between Shining Time and Thomas's island, is critically low. Unfortunately, he doesn't know how to get more. Meanwhile, Thomas is fending off attacks by the nasty diesel engines. Getting more gold dust will require help from Mr. C's slacker cousin, his new friend Lily and her morose grandfather, plus the secret engine.
| Actor | Role |
|---|---|
 Alec BaldwinMr. Conductor | Mr. Conductor |
 Peter FondaGrandpa Burnett Stone | Grandpa Burnett Stone |
 Mara WilsonLily Stone | Lily Stone |
| EEdward GlenThomas (voice) | Thomas (voice) |
 Neil CroneDiesel 10 / Gordon / Splatter / Tumbleweed (voice) | Diesel 10 / Gordon / Splatter / Tumbleweed (voice) |
 Michael E. RodgersMr. C. Junior | Mr. C. Junior |
 Britt AllcroftLady (voice) | Lady (voice) |
| KKevin FrankHenry / Dodge / Bertie / Harold (voice) | Henry / Dodge / Bertie / Harold (voice) |
 Linda BallantynePercy (voice) | Percy (voice) |
 Susan RomanJames (voice) | James (voice) |
 Colm FeoreToby (voice) | Toby (voice) |
 Cody McMainsPatch | Patch |
 Didi ConnStacy Jones | Stacy Jones |
 Russell MeansBilly Twofeathers | Billy Twofeathers |
 Lori HallierLily's Mother | Lily's Mother |
| SShelley-Elizabeth SkinnerAnnie / Clarabel (voice) | Annie / Clarabel (voice) |
| JJared WallYoung Burnett (voice) | Young Burnett (voice) |
| LLaura BowerYoung Tasha (voice) | Young Tasha (voice) |
| JJohn BellisBiker (uncredited) | Biker (uncredited) |
| DDilaMutt (uncredited) | Mutt (uncredited) |