Alan and Tricia Hamilton are blissfully happy. Until one day their perfect life is torn apart when Alan steps in front of a passing car, and he is left with a brain injury that completely transforms his personality.
| Actor | Role |
|---|---|
 David TennantAlan Hamilton | Alan Hamilton |
 Sarah ParishTricia Hamilton | Tricia Hamilton |
 Harry TreadawayDean Hamilton | Dean Hamilton |
| JJacob TheatoJoel Hamilton | Joel Hamilton |
 Jay SimpsonJohnathan | Johnathan |
 Jo McInnesGwen | Gwen |
 Jim CarterMr. Lockwood | Mr. Lockwood |
 Ron DonachieLen Hamilton | Len Hamilton |
 Anne KiddShirley Hamilton | Shirley Hamilton |
 Jo HartleyVicky Nathan | Vicky Nathan |
| CCharlotte PalmerWPC | WPC |
 Sarah PaulOT | OT |
| AAndrew WisherNeighbour 1 | Neighbour 1 |
 Sue Elliott-NicholsNeighbour 2 | Neighbour 2 |
| GGlen DaviesHeadway Volunteer | Headway Volunteer |
| DDavid MaybrickFirefighter | Firefighter |
| PPenelope BeaumontInterviewer | Interviewer |
 Pooky QuesnelHomeowner | Homeowner |