Clutching the file, Rita navigated the station's passages until she reached the office where Abdul Mansouri was leading the murder investigation. Recently graduated from a criminology postgrad scheme, this would be Abdul's inaugural stint as head of such a case. Rita had a soft spot for him; despite the bigoted speculation about being some diversity hire he often found himself working harder than the others to prove himself. But maybe not today. Knocking on the door, she heard his shocked laughter from inside.

'Come in? Rita! Jesus was just telling us all how you re-enacted the San Fermines in your living room?' Mansouri stared at her in disbelief.

'I tried to feed him some crisps and he almost gored me! She said, yeah, course you can stay with me, no problem, little did I know!' Dominguez was doubled over with hysterics. Rita felt a little annoyed and singled out, but what had she expected?

'There aren't many people willing to suffer for their principles these days, I'd have done the exact same, good for you Rita, standing up for our bovine friends,' one of the other newer recruits giggled, a 21 year old woman called Laurentia. She was Flavia's niece who had moved from Romania as a teenager.

'You should have brought him to work. We could have used him to solve crimes,' Mansouri said. Rita imagined Pepelito wandering around the station and her irritation subsided. It was funny. What a relief she wasn't facing other consequences except piss taking.

'That's what I said to your amigo when we were getting him into the truck. I said, we missed a trick, can't exactly resist arrest with a bull's horn shoved up their rear end, can they?' Dominguez slapped Rita on the back.

'How's your sister doing, you spoken to her recently? Tell her to send Castella our best wishes, will you!' Mansouri snorted. Everyone laughed, including Rita, grudgingly.

'They never speak, they haven't spoken for about ten years. Can't imagine why, I'd have thought they had lots to talk about, wouldn't you,' Dominguez said darkly.

'Anyway. Let's get back to work,' Mansouri managed to say, looking in no fit state to start at all.

'Abdul,' Rita said.

'Yes?'

'You might be interested in this. A case from eleven years ago, a murdered sex worker called Sonia Gutiérrez. It has similarities to the Caroline McKenzie killing.' Mansouri took the file.

'Thanks, Rita,' he said, turning to the autopsy report. He arranged his face into something a bit more serious.

'Yeah. The injuries found on the victim are very similar. But there's a ten year gap between murders. And the victims don't seem to have had anything in common apart from being female. One was a sex worker in her early 30s with young kids at home and the other one was a British businesswoman staying in a posh hotel.' He looked again at the file.

'What was Castella doing back then?' Mansouri asked.

'I think we can rule him out. He was on holiday in Las Vegas for 3 weeks with my sister for their honeymoon,' Rita scowled. Sonia hadn't been her case; that week, she'd had to deal with two armed robberies and a horrific hit and run. When she'd gone to visit her parents, all her mum wanted to do was gush over their holiday snaps. Her father said little and looked defeated. I should visit for his sake, she thought. She just couldn't face it.

Once back at her desk, she copied the information about Sonia to the British policewoman, plus a list of people questioned at the time. Aidan had lived and died in a different country. But the 18 year old's murder was disturbing her deeply - and so was the dart found with him. It probably wasn't bought in this area. But it was made here. No doubt taking for granted that it wouldn't be used on humans, someone would have taken pride in its 'craftsmanship'.

Heather replied, 'Thanks very much for sending this over. It's probably not what we're looking for but I'll take a look.'

Flavia had been on that case. Rita sent her a message. 'Hola. Hope you're enjoying a long deserved rest. I'm sorry to bother you. Do you remember anything about an old case, Sonia Gutiérrez?'

'Yeah, I do,' came Flavia's reply. 'That was a weird one. It was near some big conference or other. There were a few VIPs attending who I'm sure knew more than they let on. The old superintendent at the time wanted us to forget it and move on.' Of course he did, Rita thought, dead hookers weren't seen as important, especially when there was only one of them.

'There are some similarities between her death and Caroline McKenzie,' Rita wrote. Flavia was typing a lot.

Eventually, she wrote, 'Doesn't surprise me. I always thought it wasn't that bastard's first time. By the looks of it, it wasn't his last.'

*

'I told you I was gonna take you out properly,' Alfonso said when they were both home later that night. Rita got changed into a backless dress with sequins. Maybe she was too old to wear it, but fuck it. She put on some heels and they walked to Alfonso's van. He lived a 20 minute ride from the city. His house was much older and bigger than hers, and she did feel like they were rattling around. At some point, she badly needed to sort out her flat, which would feel empty and sanitised without Pepelito there.

'How was work?' he said once they were in the van.

'Hey, bad idea to ask a cop that question! It was fine. Desk duties until Wednesday. Sanchez is pissed. But not as pissed as he'd be if I'd given Pepelito to Castella.' Alfonso looked stunned.

'Your boss is an antitaurino?' he asked in surprise. Rita scoffed.

'Of course not. He doesn't give a shit. Just doesn't want the police looking bad, especially him. And our mutual friend is famous.' Rita laughed as they parked up and got out the car. Alfonso had booked a table at a pizzeria that had recently opened and did a vegan menu. They walked inside holding hands and were given a seat by the window.

'How's the goat, is she better?' Rita asked. Alfonso smiled.

'Much better.' Rita glanced at her phone before putting it away for the evening. She had a message from a number she didn't recognise, which simply said, 'Was it you? How could you do this to Javier???'

'Maybe he'll know how poor Pepelito felt now, with everyone ganging up on him,' she texted back before blocking the number. She shuddered, feeling much safer now she was staying with someone else.

'Your sister?' Alfonso said.

'Yeah.' She sighed and shook her head as their drinks came.

'Can I ask something, Rita?' She shrugged. If you said no, men would always ask anyway. She found herself becoming nervous.

'Are there other reasons you hate Castella so much?' Alfonso said. Rita stared at him; given previous terrible first dates, she had been anxiously anticipating something like a marriage proposal. Somehow this was worse. She wanted to protect Alfonso, not pollute their relationship by talking about him.

But now Castella knew.

He hadn't killed Caroline or Sonia. But he was still a dangerous psychopath.

'He is a matador so I despise him automatically, but I wondered if there's anything else.' Rita nodded and took a deep breath.

'Five years ago, we raided a property maybe about two hours from here, a huge villa owned by a drug baron called Martin Ortiz Aguilar who's now in prison.' She paused and sipped her cocktail.

'Police! Drop your weapons and come out slowly with your hands in the air!' she yelled into the megaphone, standing on the soft red carpet, shaking under her clothes. The ornately decorated walls were now riddled with bullet holes. Was her body armour good enough?

A man with a designer suit and sunglasses strode towards them. He pointed a gun at her chest. She leapt over to the side, knowing it was too late -

'Oh, go fuck yourself, bitch.'

'I was shot during the raid and spent three weeks in hospital. We lost two of our best officers that day.' Rita sighed. Her eyes were filling with tears. She remembered walking the opulent rooms, the champagne worth thousands, the ostentatious decor, gold plated furniture and diamond encrusted chandeliers Aguilar had bought with his stolen fortune just because he could.

'We found documents showing Castella owned a share in this villa and several other properties through a series of shell companies and offshore accounts. He wasn't the only one, there were other famous people and politicians. Judges too, even a bishop! Aguilar was - is - one of the most notorious gangsters in Spain. And not just Spain, he was involved with the mafia and the South American cartels. He's scum.' She took a deep breath. Her vegan pizza came, but she scarcely noticed.

'We had witnesses and we were going to throw the book at Castella for involvement in Aguilar's businesses and benefiting from the proceeds of crime. But the prosecutor's office wouldn't help us and the case was never filed. So he walked. Of course he claims his innocence.' Rita spat the words out. She dug out a photo on her phone she had found back then, of Castella, Aguilar and another drug dealer at a party in Monaco, and showed it to him. He stared in disgust.

'There's worse. Much worse.' She lowered her voice. You never knew who was listening.

'He was directly involved in running his businesses, 2nd or 3rd in command. After Aguilar went to jail, he basically took over. But we've never been able to get anything solid. He's got friends high up. Things always happen. Evidence goes missing, charges get dropped.'

'I always thought that the justice system, the prosecutors and judges, that they had the forces of right and good on their side, and that they'd work with us in putting together a case, that if officers died they'd move heaven and earth to get every last one of those who could be the slightest bit implicated,' she said coldly, as he took her hand in both of his.

'Did I get a wake-up call. I was suicidal for months. I almost left the police over it, and I joke around but being a cop is all I ever really wanted to do.' She shut her eyes.

'Why did you stay?' Alfonso asked gently. It was a good question. Rita thought about it for a few moments.

She held his gaze, feeling herself flush. 'I stayed for my colleagues at first, and then because if I left, I knew the criminals would win. Including the ones who wear a badge or sit on the judge's bench. And you know what the worst part was?'

Alfonso took her hand across the table.

'After I came out of hospital. I tried again with my sister. I turned up at her party offices unannounced and tried to give her the evidence we'd collected that he was in business with Aguilar. She started shouting that I was psychotic. Got security over to kick me out.' Rita picked up a slice of pizza and bit into it.

'Because I was related to her, my colleagues thought I was involved. Not just an animal killer. A drug dealer who's destroyed thousands of human lives. Imagine. I'd rather starve to death than take his money.' Alfonso held her hand in a warm grip. She didn't want him to get hurt.

'He's completely charmed my mum. She doesn't want to know. She's one of these people who puts 'family' above everything, so according to her, I'm the unreasonable one.' Rita swallowed hard. Sometimes she forgot how much it hurt.

'Remember all those crime scene photos and documents in my filing cabinet?' she said quietly.

'The one Pepelito knocked over that day?' Rita nodded.

'Most of the photos were from a case of two murdered drug dealers. Aguilar's ex associates, but they were known to have had disputes with Castella. One of them even wrote about the argument on his Instagram. The suspicion is, it was on his orders. The actual murderers are in jail, but they won't talk. I don't know if we'll ever have enough to convict him.' She exhaled. Did Silvio appreciate who - and what - Castella was? Dominguez said he'd tried raising the possibility of the matador trying to find 'his' missing bull; true to form, the old man was dismissive.

'Ugh. Caroline hated Castella. She hated matadors in general. She was a great researcher. Maybe she found out something she shouldn't...' He took a sip of his beer out the bottle. She shook her head.

'We've ruled him out,' she said quickly, not wanting to expose him to the awful thing swimming around in her mind. She hated herself for even asking, let alone bringing his wife into it.

But she had to know.

'Alfonso, did you or Pilar ever used to know someone called Sonia Gutiérrez?'

'Sonia?' he said. 'I've not heard her name in years. Pilar knew her from animal rights stuff, they used to go on protests together. But they lost touch. Sonia was... troubled, and Pilar used to feel guilty for not keeping in touch or making an effort. They hadn't spoken in about a year, then one day we read on Facebook she'd been murdered. They never found the killer, did they?'

She took a breath, looking Alfonso straight in the eye. Her heart jolted in her chest. 'I know this is a lot. But whoever killed her also killed Caroline - the day Pepelito escaped. Before you wonder, I know it wasn't you. At the time she died, you were helping him.'

She couldn't think what could have connected these two women.

Now she did.