He looks in the mirror. Doesn't recognise the pale, drawn face looking back at him. If he looks like he hasn't slept for six weeks then it's because he hasn't. He hasn't slept in more than brief snatches since the day of The Misunderstanding and when he does doze off he is invariably plagued by the same nightmare. He wakes up in a cold sweat, still searching for the little girl who in his dreams he is following but cannot reach. It is always a girl. Even though they never found out the sex of the baby – he'd wanted to, she'd chided him to stop being so bloody impatient – he has always imagined himself with a daughter. In his dream she has red hair like her mother's and grey eyes like his, and no matter how hard he tries he cannot catch her as she runs away from him.

'Jonny Mac' Mo is there. In these last few weeks since The Misunderstanding she has always been there. He's watched her run the gamut of emotions on his behalf – bewilderment, fury, distress – but she's always found it easier than him to show his feelings. That, as it turned out, was the whole problem. If he wasn't such an emotional retard then The Misunderstanding would never have happened and She would still be there. She would be making his life hell – that was a given – but at least he'd know where she was unlike now when the only thing that he knows is that she isn't where she should be. 'You shouldn't be working in this state'

'I'm fine' he replies. The last thing he needs is to be sent home sick because that means that he has time to think. To obsess. To try, and fail, to find her. The last time he was off work without Mo there to supervise he ended up screaming Her name outside her flat until the police were called. He didn't want that to happen again.

'You're not' she tells him firmly 'You should go home'

'To what?'

'It's not going to help matters if you end up in front of the GMC because you're not paying enough attention' she points out but then she backs down 'You can coordinate theatre and take bloods'

'Fine' he tells her. He doesn't care what he's doing, he only cares that she isn't going to send him home to face his demons.

ooooo

She isn't proud of it. At best it's betraying a friend, at worst it's gross professional misconduct, and yet she doesn't hesitate. She doesn't like rating her friends on a scale but if she did then Jonny would top the list every time, so it isn't such a stretch for her to betray another friend to help him. His happiness will always be paramount to her and right now the only way that she knows to make him happy is to fix the Godforsaken mess that he's made. She's heard about The Misunderstanding at length over the past few weeks – it's all that he can talk about – and she thinks that she knows enough about what happened to know that Jonny wasn't completely blameless. His crime might only have been being thick and a bit heavy handed but combined with the most volatile person in the history of the world it was enough to create this massive problem. It's enough to put her in a position that she never asked to be in. She doesn't want to be here, using somebody who she's come to regard as a close acquaintance if not a friend, but it's the only thing that she can think of. She's tried interrogating Sacha, Elliot and even Michael Spence but she believes them when they say that they don't know where She has gone. She's tried going to Her house and talking to the neighbours, but unsurprisingly they all seem to know her as just the strange girl at number twenty-six and nobody has even noticed that she's gone. She's tried everything else to avoid coming to this point but now she has reached the point where she doesn't feel that she had a lot of choice. Jonny will never do it himself and even if it did occur to him to do it, he doesn't have the necessary feminine wiles to wrap Mr T around his finger.

'Mo, this is a nice surprise' he seems genuinely thrilled to see her and that makes her feel even worse. She has been fending off his not terribly subtle advances for months now and now in order to get what she wants she has had to do an about face and use his feelings for her to her own ends. She doesn't feel good about it – in fact already she wants to go and scrub her skin in a hot shower until she feels clean again – but the thought of Jonny's pale face and red ringed eyes drives her on. She wants her friend back and she isn't going to get him back until somebody takes him and Jac and bangs their heads together. For that to happen she first has to work out where the hell Jac has gone.

'I just thought I'd come and say hi' she lies, flashing him an overly bright smile, wondering whether he can see the guilt that she feels oozing out of every pore.

'Well, Hi' he replies with a grin. 'How's it going up on Darwin?'

'Oh, y'know…' she shrugs '… same old, same old'

'I heard that you've been made locum consultant. Congratulations'

'Thanks' she replies, but she doesn't really mean it. She doesn't like being congratulated for her "promotion" because she's only got it because of The Misunderstanding, and she can't stand reaping any reward from something that has destroyed her friend.

'You should let me buy you a drink, to say well done' he adds eagerly and she nods her agreement.

'That would be lovely' she replies, pretending to be surprised but the truth is that this is exactly as she planned it. She knows what times he finishes his shift and she knows that every time he's seen her in the last few months he's asked her for a drink, so she has been counting on him doing the same this time. She doesn't want to lead him on but she has calculated that if they go for a drink now then he will have to go and get his coat, and that will mean him leaving her alone with his computer for long enough for her to do what she needs to do.

'Great! I'll fetch my coat' he tells her. He practically skips out of the room. As she sits down at his desk, takes the mouse and accesses his patient records she doesn't think she's ever hated herself more.

ooooo

Another night, another dozen pints in the bar. Normally Mo is there, keeping pace and helping him into a cab at the end of the night but tonight she appears to be on some kind of date with the gynaecologist. It's weird because he's sure that she's spent months trying to dodge Mr T and his advances yet now she seems to be almost encouraging. He doesn't question it too much because he's too caught up in his own misery. It is three days before Christmas, six weeks and two days since The Misunderstanding, and three weeks and four days until Jac is due to give birth to his child. For all he knows his baby has already arrived and is about to celebrate his or her first Christmas without him. If not then Jac is presumably still pregnant and cranky about it. Either way he should be there, driving her mad with his fussing, waiting anxiously for the birth of their child. It should be the best time of his life but instead it has turned into a nightmare because he doesn't know where she is.

ooooo

It takes her all night to shake off Mr T. By the time she has it is too late, and she is too drunk, to consider getting in her car and going and door-stepping Jac at the rental cottage in Holt Gorge where she has holed herself up. She doesn't tell Jonny what she's done because she knows what will happen. He'll demand the address and, drunk or not, he'll get in his car and he'll go over there. Him beating the front door down in the middle of the night, fired up by ten pints of beer and a couple of shots, will not help matters. Resolving The Misunderstanding is going to take tact, diplomacy and patience. Not Mo's strongest points but not Jonny's either and at least she isn't overwrought and sleep deprived.

When she gets in her car the next morning she pauses to consider the wisdom of what she's done. She knows that if – when – Jac realises how she's been found she will probably be baying for blood and she knows that if there's one thing more dangerous than a vindictive Jac then it's a vindictive Jac with a point. She knows that this could very easily get her and Mr T struck off and that she could just shred the address and pretend it never happened, but she also knows that it isn't that easy. Now that she knows the address there is no way to just make the knowledge go away, and she knows that if she doesn't go after Jac then every time she sees Jonny she will feel guilty because she knows that she has the ability to end his nightmare. She should be heading for the hospital but instead she calls in sick, putting on a convincingly hacking cough and a reed-thin voice that quickly convinces Elliot that she's come down with the pre-Christmas flu bug that's been going around. She has to keep up the pretence while he spends ten minutes telling her about his daughter who has had the exact same thing but eventually he rings off telling her to keep warm and stay in bed. She feels bad about him being so nice to her when she has taken the opportunity that he's given her and thrown it in his face by calling in sick almost immediately, but she doesn't dwell on it for long. She has more important things to think about, specifically what the hell she's going to say to Jac to make her come home. Telling her that Jonny is in a horrendous state won't do any good, neither will trying to resolve The Misunderstanding because that is a conversation that really needs to come from Jonny. She can't reason with Jac because when Jac's in a strop there's no talking to her and if she isn't in a strop already then she will be as soon as she realises that she's lost her little game of hide and seek. She wonders whether she'd be better off taking Jonny with her – letting him sort out his own mess because she's already gone above and beyond the call of duty for him – but she dismisses it. Jonny is a loose cannon at the best of times and she fears that if he comes face to face with Jac then he will let his mouth run away with him and no good can come of that. Better, she thinks, to try and solve things herself and give Jonny the chance of a conversation that he stands a chance of coming out of alive.

ooooo

She pulls up outside the cottage, cuts the engine and steels herself. She knows that there is no point in hanging around now that she's here, she's never been any good at procrastinating, and she knows that as long as she doesn't tell Jac how she found her the worst that can happen is that she'll be able to go back and tell Jonny that she's seen Jac and that she knows where she is. She bangs on the door but there is no answer and pressing her face against the windows she can see no sign of life. The house is clearly empty and her heart sinks. If after what she's had to do it turns out that Jac has already moved on she doesn't know what she'll do. Probably scream, cry, batter the steering wheel and then go back to Holby and pretend that this has never happened. Clutching at straws she tries the side gate, surprised when it swings open and she can creep into the back garden. She knows that this is probably trespass – a charge which, along with the gross professional misconduct, would be the final nail in the coffin of a glistening medical career – but she doesn't care. Now that she is here she is desperate to find some hint of Jac and if she needs to break and enter to do it then that is a price that she's willing to pay. She is surprised to find that the back door is open and she tiptoes into the kitchen, telling herself that if Jac can't be bothered to lock the door then it can't be breaking and entering. A glance around the kitchen tells her that Jac hasn't been gone long. Today's paper is on the side and there is fresh milk in the fridge. There is even an abandoned cup of tea on the side and it's still slightly warm. Wherever Jac has gone she hasn't been gone long and that gives Mo hope. She doesn't really want Jac coming home and finding her in the house – if that happens then the police will get called and she doesn't need to explain what she's doing here to the authorities – but at least Jac hasn't slipped her net completely. She is about to retrace her steps and head back to the car to wait for Jac to come home when she spots the patch of fluid on the floor and she knows where Jac will be.