Gemma Whelan will star in the lead role of Detective Sergeant Sarah Collins in ITV’s three-part series The Tower, adapted by Homeland writer and executive producer Patrick Harbinson.

The Tower is based on Post Mortem, the first in Kate London’s Metropolitan series of novels featuring Sarah Collins and rookie cop Lizzie Griffiths.

Harbinson (Fearless, 24, ER) will executive produce alongside Mammoth Screen’s founder and CEO Damien Timmer (The Serpent, Endeavour) and Karen Thrussell (Poldark, And Then There Were None).

Gemma is most recognised for her role in Game of Thrones and her portrayal of Karen Matthews in The Moorside. Her other recent credits include White House Farm for ITV, Emma, and Killing Eve. Gemma is currently shooting Gentleman Jack.

The Tower has been commissioned for ITV by Head of Drama Polly Hill, who will oversee the three-part drama for the channel and is produced by Windhover Films and Mammoth Screen in association with ITV Studios.

Kate London is a former Met Police Officer who finished her career working as part of a Major Investigation Team on the Homicide and Serious Crime Command.

Paul Testar (The Serpent) is producer, Sherie Myers (I May Destroy You) is co-producer, and Jim Loach (Save Me Too) is director.

In The Tower’s breath-taking opening sequence, a veteran beat cop and a teenage girl fall to their deaths from a tower block in south-east London. Left alive on the roof are a five-year-old boy and rookie police officer Lizzie Griffiths. Within hours, Lizzie has disappeared, and Detective Sergeant Sarah Collins is charged with leading the investigation. She not only has to track down Lizzie before she comes to serious harm, but also to uncover the truth behind the grisly deaths. What chain of events took two police officers and two children to the roof of that tower block - why did two of them die? Why did two of them survive?

The antagonistic relationship between the experienced Sergeant Sarah Collins and the novice cop Lizzie Griffiths is at the heart of London’s novels and The Tower. What happened on the roof of the tower is the mystery that Sarah must uncover. When it’s finally revealed, the truth will cast its shadow over Sarah and Lizzie’s relationship and their lives.

Filming will commence later this month and further casting details will be announced in due course.

Windhover Films was formed by Patrick Harbinson in January 2021. Its principals have worked in the film and TV business in London and LA for nearly thirty years. Mammoth Screen, one of the UK’s leading independent production companies, is an ITV Studios label.

The book deal to sell Kate London’s novels for TV was brokered by Luke Speed on behalf of Alice Lutyens of Curtis Brown Group.

Gemma is represented by Alexander Cooke at Hamilton Hodell and Clifford Murray at Management 360.

The Tower is distributed internationally by ITV Studios.