Four characters living in one neighbourhood in London - all living dramatically different lives, all of them on the edge - see their stories unfold.
| Actor | Role |
|---|---|
 Colin FirthMark | Mark |
 Robert CarlyleRobert | Robert |
 Anne-Marie DuffMichelle | Michelle |
 Nicholas BurnsMichael | Michael |
 Emilia FoxLaura | Laura |
 David OyelowoYemi | Yemi |
 Julia DavisSally | Sally |
 Emily WoofSandra | Sandra |
| PPeter McNeil O'ConnorHostel Manager | Hostel Manager |
 Charlie Creed-MilesMan in Hostel | Man in Hostel |
 Megan DoddsAnastasia | Anastasia |
 Toby KebbellBeggar 2 | Beggar 2 |
 Gugu Mbatha-RawGirl at King's Cross Station | Girl at King's Cross Station |
 Nikki Amuka-BirdItshe | Itshe |
 Nichola BurleyZoe | Zoe |
 Alan MandelThug | Thug |
 Pearce QuigleyBeggar 1 | Beggar 1 |
| GGemma BarrettDanielle | Danielle |
| AAnne-Marie BossmanAdanna | Adanna |
| MMarguerite Fontaine-AnselmHousing Officer | Housing Officer |
| AAntonio PelayoKitchen Cleaner | Kitchen Cleaner |
| MMaz AlbrechtSelf | Self |
| JJoanne AdamsShop Assistant | Shop Assistant |
| RRia HaydonMidwife | Midwife |
| CCatherine RaingoldSocial Worker | Social Worker |
| LLaurence RichardsonPolice Officer | Police Officer |
| TToni-Ann WalkerTaxi Driver | Taxi Driver |
 Chris WilsonPolice Officer | Police Officer |