A young man ushers an older woman into a dark exploration of her past - back to the time when, as a young girl, she met a stranger who affected her life forever.
| Actor | Role |
|---|---|
 Maggie SmithMary Gilbert | Mary Gilbert |
 Ruth WilsonYoung Mary | Young Mary |
 David WalliamsGreville White | Greville White |
 Gemma ArtertonLiza | Liza |
 Michael ByersZach | Zach |
 Danny Lee WynterJoe | Joe |
 Max DowlerMr. Graham | Mr. Graham |
| RRebecca BottoneSinger | Singer |