Ludwig episode 3 sees John "Ludwig" Taylor (David Mitchell) investigate the murder of a guide during a walking tour of Cambridge, while Lucy Betts-Taylor (Anna Maxwell Martin) starts to believe they're in the middle of a conspiracy. Here's everything that happened (spoilers ahead)...
The episode opens with a tour group in a church. The tour guide pulls back a curtain to reveal a beautiful stained glass window… and the body of another tour guide!
John looks distressed as the body is bagged up and removed from the church. The victim was a 21-year-old American student called Megan (Call the Midwife's Ella Bruccoleri). The church was the last stop on the tour she gave her group of Cambridge.
John returns to Lucy's in the evening. Lucy reveals she's discovered that Sinclair was a conspiracy theorist. Lucy scolds John for not getting closer to DI Russell Carter (Dipo Ola). He replies that he did indeed attempt some casual conversation with Russell. "Do you like football at all?" was John's attempt. Lucy is suspicious of how Russell turned up just as James vanished and is taking secret calls from the Chief Constable.
Lucy says she can't find much about Russell online. She also looked into the Sinclair burglar, Rhys Bowen, and has discovered his mother is trying to fund an appeal. Lucy says she plans to pretend to be a journalist to meet the mother with the goal of meeting Rhys in prison. John is not impressed by this dangerous plan.
In the station, Russell says he now has a list of suspects for the church murder — all the people on the tour. DCS Carol Shaw (Dorothy Atkinson) then bursts in and says she needs three officers for an emergency task force to find the son of a missing millionaire. The son sounds like a nightmare but, with a knowing nod towards the Chief Constable, Shaw makes clear the family has influential friends.
The Chief Constable (Ralph Ineson) then asks John to show him what he's got on the church murder. He explains how he's trying to work out what everyone could see in the church, which has lots of blind spots due to the pillars. He then explains that the puzzle is impossible. John then stuns the Chief Constable by saying he's not looked into motives. Oddly, Russell walks off with the Chief Constable, while Shaw tells John the motive matters! "Find it!" she sternly tells him.
Lucy goes to interview the burglar's mum. She says Rhys was with her the whole evening the night of the crime but the police didn't believe her. "It makes no sense," says the mum. She admits Rhys is a burglar but says he wouldn’t hurt anyone.
John, after another failed attempt at conversation with Russell, heads to the interview room where he meets Mr and Mrs Tate, who say they're shocked to hear about the murder.
We flashback to their tour group. We see the happy victim and Mr and Mrs Tate, who say it's their anniversary. Also part of the group are three French ladies who are part of the same family. Plus there are two people from the Isle of Man.
Mr Tate admits feeling a bit cheap getting his wife a walking tour for their 30th wedding anniversary. But John seems to think that sounds ok! The team is still trying to track down the victim’s phone.
In the interview room, John and Russell question the three French women. The grandmother, the mother and the daughter it's revealed all have had their hearts broken recently. They say the victim was happy and bubbly.
Next, they interview the Isle of Man pair, both upset at the news she was killed while they were there. "She was my best friend!" John and Russell are shocked… after one day! But then they reveal they shared halls of residence with her last year. They reveal that she'd text them if she was short on numbers and they'd come along on the tour.
They say the last time they saw her was in the church. It's revealed that the French granddaughter went to speak to the victim.
Alice is convinced the pair who knew the victim before must be the killers as they’re the only ones who know her. John says that doesn't matter. He believes it wasn't planned in advance. He says you wouldn't plan to murder someone in front of six potential witnesses and "write your email address down for good measure". John says the motive formed during the tour itself.
Back at Lucy's, John tells her about Ziegler and Carter talking in private. Lucy tells John about the burglar suddenly signing a confession despite his mother saying he was in all evening. Henry thinks blogger Sinclair was about to break a story but they got to him first. "Who did?" asks John. Henry hasn't got an answer. Lucy is feeling guilty about lying to the mother of the burglar. John tries to reassure her.
John picks up a book in Henry’s room: "The Curious Life of Birds" (might this book be the key to cracking his brother's code?). He tells Henry that it was his book and he'd been obsessed with it growing up. Lucy listens at the door as John says he has left it too late to ever get married.
Back at the station, John learns the missing millionaire's son has been found dead. He apparently drowned in a river. He'd been camping out in one of his dad's developments and there was drug paraphernalia found. Ziegler broke the news to the family in person, which is unusual. Holly produces the victim’s phone records. John spots that at the time the victim was murdered someone used her phone to make a call to Paris.
They bring the three French women into the station and the youngest says she's been texting her ex-boyfriend again and that's his number. She explains that her battery died and she desperately wanted to reply to his message, so she borrowed the victim's phone. It then turns out the grandma has also been swapping messages with a man! The daughter, not impressed with her flirty relations breaking the code of the trip being a girls' only adventure, then asks Russell out! Russell lies that he's married to get out of the situation.
John still believes the phone is the key. "The killer must have taken it for a reason," he says. He remembers she was taking photos with her phone… "We need to go back to the church."
Lucy goes to the burglar's house. But after a quick conversation, the mother closes the door on her.
Outside the church, John suggests the best way to see what the dead guide might have photographed is to walk the tour themselves. Russell isn't impressed!
At the last stop on the tour, John spots something crucial. He says to Russell they should gather the suspects together in the church and bring along Ziegler, after all, he wants to see John perform miracles and a church seems fitting.
"Make this good!" warns Shaw as she comes into the church with the Chief Constable. John explains that it seemed impossible that something during a walking tour could turn someone into a killer and that's because the twist in the riddle was that the person was already a killer.
The double murderer is revealed
John says that the other victim in the double murder was the millionaire's son, Jordan. John says he's discovered three coincidences and that is statistically significant, demonstrating that they're probably not coincidences at all. The first is the location of the final photo stop on the tour being the site of where the ill-fated Jordan had been camping out in. He says the second coincidence was the crucial phone being missing and the third was that the building where Jordan had been camping was protected by Cambridge Complete Security, the firm Mr Tate works for. "Your connection to both events is a coincidence too far Mr Tate," says John.
After being told they can use evidence from his security top, Mr Tate confesses. He says he was doing his rounds when Jordan attacked him. His desperate wife tells him it was self-defence. Ziegler points out Jordan took thousands of pounds from his dad and Mr Tate admits taking it.
From the window, Mr Tate saw the tour guide, on an earlier tour to the one he attended, taking photos that could have shown him killing Jordan.
So he booked the walking tour to get hold of her phone. After failing to get the phone during the tour, at the end of it he tried to grab the phone from her in the church and struck her dead. Mr Tate is handcuffed and led away.
In the car, Russell tells John he was engaged but she died. This explains why he got so upset when John previously quizzed him over marriage. Turns out he was engaged to the Chief Constable's daughter, thus explaining why he's been talking to him in private.
An emotional Lucy reveals that the man arrested for Sinclair's murder — the burglar — has been found dead in his cell. She believes someone killed him, John's not convinced. John dismisses Lucy's idea that shadowy figures are following them but then we see someone take a photo of John! Who is it?