The hit crime drama that critics have described as “the BBC at its best”, which is also the broadcaster’s top-rated series, is returning to our screens. Strike: The Running Grave, the seventh book in the Cormoran Strike series, will be adapted for TV, and it is bringing some familiar faces back with it.

Tom Burke and Holliday Grainger will reprise their roles as Detective Cormoran Strike and trusty assistant Robin Ellacott – and they have quite the storyline to unpack in the new series. Series 7 will see the duo tasked with helping a worried father in a bid to rescue his son from a religious cult in the Norfolk countryside, with Robin entering the cult herself.

The synopsis reads: “In Strike: The Running Grave, Cormoran Strike is hired by a father to locate his son, Will, who has joined the religious cult known as the Universal Humanitarian Church (UHC). To investigate the deeply sinister undertones and suspicious deaths surrounding the UHC, Robin Ellacott goes undercover at the cult’s remote Norfolk headquarters, uncovering dangers and trauma that take a devastating toll on her.”

The beloved drama is based on the Cormoran Strike book series, written by J. K. Rowling under the pseudonym Robert Galbraith. The first series, The Cuckoo’s Calling, first aired on the BBC in 2017 and was an instant hit with viewers.

For those who may be new to the series, the crime drama follows private investigator and war veteran Cormoran Strike (Tom Burke) and his assistant Robin Ellacott (Holliday Grainger), who use their specific skills and backgrounds to investigate complex cases that the London police have not been able to solve.

Six series have aired to date, with Kerr Logan, Killian Scott, Ben Crompton, and Natasha O’Keeffe also being among the recurring cast.

The Independent previously said in a review: “Strike: Troubled Blood, in other words, is the BBC at its best, and now, as in the 1970s, the corporation is one of the few things in this benighted nation that actually works and is world-class.”

The source material for the drama has been hailed and, in fact, all seven Strike novels topped the national and international bestseller lists, selling more than 20 million copies worldwide across all editions. The TV adaptations have been devoured by audiences, leading them to become one of the UK’s most-watched dramas. Critics have described it as both “an extraordinarily fine drama” and “brilliantly acted”.

A release date has not yet been announced, but with filming underway, it could drop later this year.

For now, you can catch up on series one to six on BBC iPlayer.