Anguish ripples through East London in Unforgotten's sixth season, when a dismembered spine is dredged out of Whitney Marsh. After breaking the ice in the ITV drama's fifth season, Sunny and Jess delve deep into their second cold case as a team, with actors Sanjeev Bhaskar and Sinéad Keenan reprising their roles as DI Sunny Khan and DCI Jessie James. The series kicks off six months after the pair's pivotal heart-to-heart, when a spine is found in Whitney Marsh. Pathologist Dr Leanne Balcombe (played by Georgia MacKenzie), makes a rare discovery.

Leanne tells Sunny and Jess that the spine bears a Harrington rod, which was used to treat scoliosis. She then delivers grim news - the spine was dismembered before being hurled into the Marsh. Speaking about their new investigation on Unforgotten, Sanjeev Bhaskar explains Sunny and Jess "trust each other now in a way they didn’t before." He says: "they're in a better place than they are.". Though Jess still keeps her distance. "They’re closer, but she’s reticent about going back to that discussion," Sinéad Keenan argues. "Sometimes, after a deep conversation, you instinctively pull back. That’s where she is.".

On the hunt for more body parts, Jess and Sunny soon discover a severed leg with a lacerated femoral artery - which Leanne points as the likely cause of death. Four suspects emerge throughout the investigation, with newcomer Max Fairley - who was diagnosed with high-functioning autism - making a trailblazing acting debut as Marty Baines. Max faced the intensity of a police interview during filming, paving the way for an eye-opening moment for Sanjeev behind the scenes. "The pressure he was under manifested through him tying a thread from his coat", he says.

This self-stimulating behaviour, or "stim", is an example of repetitive behaviours that autistic people use to self-soothe or manage their energy. Stims can involve movements, sounds and the use of objects. Sanjeev knew his limits: "Interview scenes bring in their own emotional intensity, you don’t want to push if it’s giving them pain.". Sunny endured hardship in season 5 of the long-running show, from his grief over Cassie’s death to the breakdown of his relationship with Sal (Michelle Bonnard). Rest assured - this season sees the Elvis-loving inspector bounce back to life.

"He's in a slightly more positive place than he was”, Sanjeev says, “he’s managed his grief over Cassie." After mourning for his former partner, Sunny makes an effort to bond with his daughters and even takes himself out for dinner. "I couldn't go to the cinema on my own!", admirative Sanjeev confesses. Sunny could also explore a romantic spark with Leanne. "Who knows? They were the last two people to see Cassie. There is a connection", Sanjeev hints.

Jess, on the other hand, is dealing with the consequences of choosing to mend her marriage with Steve (Andrew Lancel). Last season saw the new DCI struggle when he revealed he’d had an affair. Despite the betrayal, Jess chose to stay, though fans wondered if she’d made the right decision. "That’s a question I also ask myself," Sinéad says. Steve turns on the charm this season, greeting her with a warm dinner and wine as she returns home. But when duty calls, Jess cancels last-minute, rushing to Whitney Marsh and back to work.

Torn between her family’s well-being and her duty, Jess deals with the consequences of her choice. "She’s chosen to try and make it work, but it’s clearly not in a good place," Sinéad warns. This series also sees compelling performances from established actors in the likes of The Crown's Victoria Hamilton and MyAnna Buring. The cast of suspects is completed by Max Fairley and TV newcomer Elham Ehsas as Asif, an Afghan man training for his UK citizenship test.