Silent Witness season 28 episode 8 recap: What's killing the passengers?

Silent Witness season 28 episode episode 8 sees Nikki (Emilia Fox) trapped on a plane with passengers dying in mystery circumstances. Ex-Strictly and Casualty star Sunetra Sarker guests.

We're on the plane, and annoying Grant (Paul Hilton) throws up. Poor Nikki is asleep, not sure how given what's going on! She gets woken up again and told Grant needs help. "It could be airborne," says Nikki, noting Grant was sitting next to the now-dead Tony. "We’re all at risk," says the steward.

In Mumbai, a man in a biohazard suit inspects the body of the cleaner found in the hotel room in the first episode. Then comes in the pathologist, who's not surprisingly very cautious. He notes a hand injury that could have been caused by contact with a chemical. He takes some blood. Back on the plane, the pilot turns off the wi-fi to stop the passengers from posting stuff about what’s happening on social media. Nurse Beth isn’t looking well.

Why isn't Nikki sick too?

Meanwhile, Harriet says everything is pointing to a highly poisonous toxin. The pathologist says they shouldn't jump to conclusions. Nikki is wondering why she isn’t getting sick despite being with Tony. She goes to find Beth and tracks her down to a toilet. Beth is on the floor with blood all over her face.

Back at the Lyell, Kit says she's found out Tony oddly has no digital footprint. Kit says the owner of the plane firm also owned a luxury development company in Karachi that went bankrupt and lost loads of money. The owner of the investment company that invested in the project vowed to bring him down and the investment company owner turns out to be ex-military, who runs a covert anti-terrorism unit. They are known to assassinate people using poison! "The owner of East West Airlines made an enemy of the general who poisons people," says Jack, summing it up nicely for lost viewers! So, would he have poisoned a whole plane full of people in revenge? Jack wonders if they could be looking at a military-grade nerve agent.

Beth and Grant look close to death

On the plane, Beth and Grant aren't looking good. At the Lyell, Fiona Mason (Sunetra Sarker), from Foreign Office Special Services, barges her way in. Jack fills in Fiona about their theory about the ex-military chap. Harriet suggests perhaps the cleaner infected Tony who then infected the passengers on the plane. Kit says Tony had never been further than Margate, but then randomly took a three-day trip to India, leaving economy class but returning business class. What was Tony doing?

Jack gets angry and says they need to warn Nikki. Fiona says they shouldn't. She reveals that the Pakistani Prime Minister is on his way to London and she says the events on the flight could be linked to his visit. She says the airline's owner is a vocal supporter of the PM and the ex-general isn't. Jack says he will call Nikki, but a security official blocks him and Fiona tells him he can't. She demands Jack’s phone. Jack is not happy. He tries to use a landline, but they’ve been blocked.

Harriet has a burner phone

On the plane, Nikki gets emotional talking to the steward, Ade (Gershwyn Eustache) and says she wants to get back to Jack and her work. At the Lyell, Jack says he's worked out why Fiona was being so tough. He says if everyone starts falling sick on the plane they won't let it land. And they don't want that information leaking to Nikki and the people on the plane. Turns out Harriet has a burner phone! She says it was her secret phone to bet on horses as her husband didn't approve! She tells Jack to use that. "It's always good to have a few secrets in a marriage," she tells Jack.

On the plane, Grant manages to be annoying even when ill. He's now confused and doesn't know who Nikki is. Jack phones Nikki and tells her they think it could be a targeted poisoning. He says Tony could be involved. Nikki tells him that Tony said something strange about having something to live for after the deaths of his wife and daughter. She also recalls him saying victory just before he died. Nikki says she wants to look at Tony's body to see if something has happened to it which could tell her what the toxin is. Jack’s not happy. Fiona and her team of armed police raid a London shop looking for toxic substances. Nikki heads into the hold to inspect the body and says to lock her in so she doesn’t put anyone at risk when she inspects the body.

The truth about Beth and Tony is revealed

At the Lyell, Kit has dug into Tony's financial past and found he was taken to a small claims court by a medical supplies company in Essex. "There’s something else going on here," says Jack. In the hold, Nikki inspects Tony's body. Nikki finds a perfume atomizer in Tony's pocket. The bottle has a few drops of liquid remaining. She sees a mark nearby on his body suggesting whatever was in the bottle leaked onto his skin. She believes the bottle contains the toxin.

The passengers, including the now not very chilled-out climbers, are demanding the steward tell them what's going on before Nikki's allowed back up from the hold. Finally, they allow her out. Nikki reassures the passengers.

Jack and Kit go to Tony’s house and speak to his neighbor, who isn't much help. They pass a local charity shop and there's a photo on the window of Tony with a big charity cheque. They go inside to speak to a woman working in the shop. She asks if they can they can give Tony his coat, which he left in the shop. Jack takes the coat and outside the shop checks the pockets and there’s an address.

Beth tells Nikki some people do deserve to die. She's not making a lot of sense. She says Grant knows what's inside the bottle. Jack and Kit manage to break into Tony’s house. In his office, Tony has files saying: "Victory" as Jack notes, the last thing he said before his death. There's also something saying "Berkshire Biofuels" and we know Grant works in biofuels! Kit and Jack go to Victory Wharf, where the biofuel factory is, which is very close to Tony’s house.

We go back in time and see Beth spraying a substance, we assume the toxin on her hand, and then we see her touch Grant’s hand. In the present, Nikki asks her why she would poison Grant. "I can stop this," says Beth. “I have an antitoxin." But she wants Grant to confess to something, not clear what. Jack phones Nikki. He says Tony blames his daughter's death on Berkshire Biofuels, which Grant is involved in. Grant is the target. "I know why this is happening, it's because of the nyraxin," says Grant. "They blame me." "What's nyraxin?" asks Nikki. Beth demands Grant admit he's to blame for the deadly substance.

Beth says it killed her child as well as Tony's. Beth and Tony both lived near Grant's factory and believed the substance got out of the factory and killed their children. "No proof," says Grant. Beth says it's nyraxin in the bottle and describes how it kills you. "Proof," Beth shouts back. Nikki asks why do it on a plane with all these passengers placed in danger, Beth says it was their only chance to get close to Grant. Beth said they found a chemist in Mumbai to produce the poison. Nikki fumes that they killed a cleaner. Grant cracks and says he did whatever she says he did. Beth then drops the bombshell she doesn't actually have an antitoxin. "I'm sorry, but we're both going to die," she tells Grant.

Harriet investigates what nyraxin is and how it might be cured. Harriet says eye drops or travel sickness pills have a substance that will work! Nikki gets a load from the passengers on board. Nikki gives a mixture to Grant, but Beth refuses it and she collapses while remembering her son. Nikki tries to save her but she dies.

In London, the plane has landed and we see a lot of people in biohazard suits. Grant is oddly in a police car it appears. Surely he'd be taken to hospital? Nikki and Jack are finally reunited. It’s clear Grant’s factory is being investigated.

Sometime later, Nikki and Jack — who seem to love a romantic walk around a graveyard! — visit Beth's grave as Nikki explains Tony used the last of his money for a plot so the victims could be together. Nikki and Jack kiss.