Was Boston a master criminal or was he just a lucky one? As Paradise concludes, Dan and Stephen examine the breaks Boston received that allowed him to escape justice for 38 years.

As the podcast nears its conclusion, fresh information kept hidden in UK Foreign Office files for 40 years delivers yet another twist to this case.

Vince, Penny and Dan head out to the remote island of Hunting Caye, where Peta and Chris were last seen alive.

They find a near deserted paradise, far removed from any sense of danger. But as they sit and talk, Vince reveals disturbing new details about his father.

Leaving Belize and Vince behind, Penny and Dan go on to the port city of Puerto Barrios in Guatemala in the hope, more than expectation, of finding Chris and Peta’s lost graves.

What they discover at the cemetery leaves them with a creeping sense of unease about the information they'd been given – and the investigation the FBI led.

As Dan heads to Belize, hopes of finding Chris and Peta’s graves in Guatemala fade with new information about the lengths the FBI went to in their attempts to find them.

Dan heads to Sandwich in Kent to meet Blaise and Jenny, Peta’s eldest brother and sister-in-law. He hears where Peta got her stoicism from and learns that Blaise was never told that the FBI failed to find the graves.

Back in the States, Detective Amy Crosby hands over files that contain a vital clue to what happened on the Justin B – and raise the possibility of there being two more victims, ‘the Vikings’

Meanwhile, Annie finds the Bombero who pulled the bodies from the water in ’78. What he tells her only leaves us asking more questions - and there’s a troubling inconsistency that clashes with Vince and Russell’s account.

The episode ends with a startling breakthrough that gives us hope we could actually locate the graves of Chris and Peta that the FBI failed to find.

Find out more about the case here: www.bbc.co.uk/paradise

Dan travels to Oxfordshire to meet Penny and her mother, Audrey, who by now is in her nineties. He hears how Audrey and her late husband, Charles, painstakingly tracked down information about Chris and Peta's whereabouts and made appeals on radio and TV.

Back in Greater Manchester, the now retired detective, David Sacks, talks about the investigation he conducted, with the help of Charles Farmer, that centred in on Silas Duane Boston. It's his file, sent to the US in 1979, that Boston's lawyer, Lexi Negin, says contained all the details necessary to frame her client. But were details in that file ever leaked? Dan tracks down the officer in the US who received it, Jim Kelly, to find out.

It's in speaking to Jim Kelly that Dan learns a startling revelation that explains why the case went cold for so long. And it appears Vince and Russell's former step mum, Kathe, may hold the key to closing out Lexi's defence - or maybe there's another way of solving this case.

Find out more about the case here: www.bbc.co.uk/paradise

We visit Boston’s half-sister, Arthene, and hear about his childhood growing up surrounded by criminality.

A remarkable set of coincidences on both sides of the Atlantic sees Boston arrested after 38 years but with crucial evidence buried, how watertight is this case?

Find out more about the case here: www.bbc.co.uk/paradise

Vince speaks about his mother’s disappearance in 1968 – and how his own grandmother told him what had happened to her.

Find out more about the case here: www.bbc.co.uk/paradise

Stephen and Dan head to Savannah, Georgia to meet Vince Boston – son of suspect Silas Duane Boston. Vince (then 13) and his younger brother, Russell (12), were on board the ‘Justin B’ with their dad, when they met Chris and Peta in June 1978.

Find out more about the case here: www.bbc.co.uk/paradise