His call to her again goes to voicemail, and this time he leaves a brief message.

"Ruth. I'm at the restaurant now. I'm now opening the door, and Maxim is about to take my coat."

It is there he ends the message, as he closes his phone, and nods to Maxim.

"Your lady is not here yet, sir," Maxim says in his slurred voice. He and Ruth had laughed the first time they'd come here. The maitre d' who is always drunk, he had called him, while Ruth had corrected him, pointing out that many Frenchmen speak that way, whether drunk or not.

"The French accent is no doubt part of his act …... his legend, if you wish. I'll bet his real name is Martin, and he comes from Sheffield," he had quipped, and Ruth had gently kicked him under the table, because as he'd spoken, Maxim had appeared beside him with their wine.

Maxim shows him to their table – the same one they ask for each time Harry makes their booking …... at the back of the room, in the corner. Out of the way, private, where they can hold hands and gaze into one another's eyes …... it is somewhere they can feel and act like any normal couple, who have just had a normal day at work, and wish to spend a normal evening out with one another.

Harry has ordered a whiskey, and has his eyes fixed on the door. He considers ringing her again, but he knows there will be a very good explanation for Ruth being twenty minutes late for their date.

And there is, but he doesn't yet know what it is.

Harry sits over his whiskey, contemplating the turn of events which had led to Ruth accepting his dinner invitation six weeks ago.

Alright, so asking her to marry him at Ros's funeral had not been his best idea. His best idea had been to forget about marriage for the time being, and to one night after work, ask her to join him for a drink. To his relief and barely suppressed joy, she'd said yes. Afterwards they had strolled along the embankment until light rain had begun to fall, and so he'd grabbed her hand while they'd run for a taxi. They had tumbled into the back seat of the taxi, laughing, and when he'd found her face close to his own, he had kissed her lightly, and she had not pulled away. Better than that, she had returned the kiss, until they heard the taxi driver ask: `Where to, sir?'

Ruth had recovered from the kiss first, sitting up and giving the taxi driver Harry's address.

"You know where I live? How?"

"The same way you know where I live," she had said, tapping the side of her nose, and then the taxi had quickly pulled into the stream of traffic, throwing her against him all over again. He'd placed his hands on her waist to prevent him kissing her again. His plan had always been to move slowly with her. He hadn't wanted to scare her off. He hadn't wanted to risk losing her all over again.

Which is why they have only been seeing one another once or twice a week, and they still have a celibate relationship. As difficult as he is finding this, he is certain it will be worth it in the end. To Harry, the reason for this is simple. For anything more to happen between them, he wants Ruth to want him as much as he wants her.

Suddenly, Harry has an idea, so he takes his phone to the alcove just inside the front door, and makes a call.

"Tariq, I have a job for you. You know that new software we all have on our phones? I need you to find Ruth for me …... and no, I'm not stalking her. We're meant to be having dinner together, and she's almost a half hour late, and that's not like her. Yes. Thank you." And Harry hangs up, and waits.

Two minutes later, Tariq rings him back, and what he tells him send chills down Harry's spine.

Harry rattles off a list of orders to Tariq, and no sooner has he hung up, than his phone rings. He is so relieved to see Ruth's name appear on his caller display that he almost cries.

"Ruth, where are you. Just tell me, and I'll come and get you. Are you alright?" he says.

"Sir Harry. So lovely to be speaking with you again. I'm sorry to be using Ms Evershed's phone, but I needed to be sure you'd answer." Male. Clipped accent. German? Dutch? Danish? "You probably don't remember me. I have your Ruth, and she's a fiery one."

Harry feels a sudden surge of heat and anger suffuse his body. He thinks he knows who this is, or at least, Harry believes that he knows his association with this man.

"Who are you?"

"You must remember Thomas Bergen. German Minister for the Interior, murdered in Cologne in November 1979."

"Yes," Harry whispers, "I remember." What kind of fanatic waits 31 years to carry out his idea of revenge?

"I am Klaus. I was 14 when my father died. Do you know what happened to my mother?"

"Look, whatever you think I did back in 1979, you're wrong. That bombing, as tragic as it was, was not the work of MI5."

"Then whose work was it?"

"You have to look closer to home, Klaus. Your own government were -"

"Do you know that they raped my mother? They raped her while I was forced to watch. They raped her because to kill my father was not enough."

"I'm so sorry you had to experience that, Klaus, but I reiterate …... that was not the doing of MI5. I did not give those orders. My people were not involved."

"I've been waiting for over twenty years for you to form a relationship with a women who matters to you. You are a sad bastard, Harry. Most men in your line of work have a wife and at the very minimum, one mistress. You have had neither for far too long."

Harry's stomach clenches. He knows what this is about. He knows what Bergen plans, and he doesn't want Harry on the end of a phone. He needs him there, in the same room as Ruth …... and he …... and whomever else he has ready to violate Ruth.

"Where are you?" Harry asks.

The address Bergen gives him is the same address in Wapping given him by Tariq. "And if I get even a sniff of CO19 or any of your other agents, I will wait until you are here, and kill her myself. Nothing would give me more pleasure."

Harry has no idea what atrocities – if any – Ruth has already been subjected to. He has to get to the address in record time, and he has to ring Tariq and Lucas. Then he has to leave it up to his team to make the decisions. He is emotionally compromised. He is not at his best.

But he cannot allow himself to fall apart. Ruth needs him to be calm and confident.

Calm? Confident? Who is he kidding? He can't stand by and watch while Ruth is sacrificed on his behalf. Not again.