Ashitey (pictured left), Näthe and McAdams (pictured right) join lead actor and executive producer Idris Elba, along with other regular actors Toby Jones, Lisa Vicari and Christiane Paul.
Plot details about season two are still being kept under wraps. Filming is currently taking place in the United Kingdom.
The second season is produced by Jamie Laurenson, Hakan Kousetta and Tom Nash at 60Forty Films, alongside executive producers George Kay and Jim Field Smith, with Field Smith's own production company Idiotlamp Productions.
Season one received a good rating on Rotten Tomatoes and landed on the Nielsen Streaming Originals Top 10 list. The series was created by George Kay and Jim Field Smith, and Field Smith is also the lead director. Guy Bolton is the head writer.
Ashitey was most recently seen in a guest role on Apple TV+'s Constellation. She was part of the cast of Sky Atlantic's Riviera season three, starring Julia Stiles. Other television roles have included Netflix's Seven Seconds, Channel 4/Netflix's Top Boy and the BBC's Doctor Who.
Karima McAdams had a regular role in the British thriller series Deep State and played guest roles in Netflix's Vikings and Prime Video's The Wheel of Time, among others.