InfinityAndOne, I think Mac has come close to confessing a couple of times. If Cal and Ethan's investigations are making him feel as trapped as he felt the day he confessed to Charlie and Noel, it could happen, but I'm trying to think of a way the boys could figure it out for themselves. Thank you for your review.

X-Sammii-X, David is too sensible and too nice as well - I can't see him stealing and causing someone who's in pain to suffer. Though Mac can be really kind too! Cal and Ethan did ask Lily to help them, but she is kind of taking over now! Yes, Big Mac's words could be interpreted as a confession. Thank you for your review.

Bonnie Sveen Fan, I'm glad you like Cal and Ethan's banter - I don't like it when they have a real argument that ends with them hating each other, but I do love the moments when they wind each other up! I don't think Mac does want them to find the culprit. Thank you for your review.

Tanith Panic, thank you for your review. I think it depends on the colleague - telling Noel was relatively easy for Mac because he's Mac's best mate and always supports him, but Cal sees Charlie as a father figure, so anything might happen if Mac tells him! Robyn's objections to celibacy are somehow so inoffensive and non-judgemental.

westlife4ever80, thank you for your review. I think you're right - at the moment, Cal sees it almost as a game and hasn't considered that it might actually be very painful to find out something like that about a colleague. Ethan's more aware, but it's going to be a shock.

"If you know the name of the patient, we can probably find out who Mac meant," said Lily. "But we already know it was Louise or Jacob." She frowned thoughtfully. "Or Mac."

Cal stared at him. "It can't be Mac. If Mac was the thief, he'd have told us who it was, wouldn't he? Think about it. Whoever is behind this is happily letting Charlie take the blame. If it's Mac and he knew we were narrowing it down and he was still on the list, don't you think he's going to jump at the chance to throw suspicion onto another person?"

Ethan looked at Lily. "I do think Cal has a point. Mac had four people to choose from, but he wouldn't do it."

Lily looked startled. "Four?!"

"Um, well, Cal actually said your name and also David's," said Ethan apologetically. "I don't know why, but-"

"That was just a test!" said Cal defensively. "If Mac was lying about someone being there, he'd pick a name randomly. If he'd said Louise or Jacob, it would have proved he doesn't have a problem with dropping his colleagues in it. If he'd said Lily, we'd have known he was lying, which calls everything he's said said into question. And if he'd said David, he'd have contradicted himself, which would mean he was really tying himself in knots."

Ethan smiled slightly. "That was rather clever of you."

"Do you have to sound so surprised?"

Lily thought for a moment. "We can check the patient's file. If that is inconclusive, we can ask Dr Gardner who she was working with. But I think we need to talk to Jacob first."

Cal, Ethan and Lily managed to intercept Jacob on his way to Connie's office.

"Ah, it's Nancy Drew and the Hardy Boys," said Jacob with a big smile. "Have you worked it out yet? Did I do it?"

Ethan laughed. "The Hardy Boys. That's quite clever actually."

"We would like to know what you were doing on the afternoon of 28th July," said Lily.

"The 28th July." Jacob frowned and rubbed his chin thoughtfully in a way that made it very clear he was messing about. "What was I doing?" His face broke into a smile. "Why don't you tell me, Dr Knight."

Cal wished he could have told him. It would be brilliant to be able to work out what they were all doing without even questioning them.

"We would like to hear it from you, please, Staff Nurse Masters," said Lily icily.

Jacob looked at her for a moment and his smile faded. "What? You're being serious, aren't you?"

"Of course we're being serious!" said Cal.

"I thought you were just having fun," said Jacob. He looked slightly confused. "I mean, seeing as you and I, Dr Knight, were working together at the time; considering I didn't leave the patient's side until her husband arrived, just minutes before Charlie was frogmarched out of the hospital - which you'll be able to confirm from reading the feedback the patient left – I did think you were just messing around."

"You two are hopeless!" said Lily. "You were actually alibis for two of our suspects and you didn't even know."

"One day is very like another in the ED!" said Cal. "We don't all have your memory, you know."

Ethan was looking stressed. "Please don't fight. We need to decide what we're going to do next."

"Who's fighting?" said Cal.

"I'm not fighting." Lily folded her arms.

Ethan rubbed at one of his temples.

"Ethan, are you okay?" Cal knelt beside him.

"I've got a headache," said Ethan. "That's all."

Cal thought guiltily that they had been pushing Ethan pretty hard today. "Maybe you should go home, Ethan. Get some rest."

"'Get some rest'? You sound like someone in a TV hospital soap," said Ethan.

Cal tried not to smile. If Ethan was this moody, he really wasn't feeling great, but Nibbles in a mood was always funny. "Why not have a lie down in the staff room?"

Ethan glared at him. "You're not shutting me out of this, Caleb."

"Okay. You go and have a rest and I'll do some work," said Cal.

"I don't need a rest!" said Ethan huffily, but his lip was wobbling.

Lily cut in swiftly. "I have an idea. There is one place we haven't visited; one group of people we haven't talked to."

"Who?" said Cal. You mean the paramedics? I suppose they are in and out of Resus, but how would they have known that the relative had tramadol?"

"No, not the paramedics," said Lily. "But I don't think this is a job for any of us."

Robyn looked excited when Cal and Ethan approached and asked to speak to her. "Is it my turn now? My turn to be questioned?"

"No, but we want you to perform a special task for us," said Cal. "You're the only person in the whole hospital who can do it."

Robyn's eyes grew round. "What is it?"

"Meet us in Ethan's naughty cupboard in twenty minutes and we'll tell you."

Robyn backed away. "Sorry. I'm not into all that."

"Don't worry. It's nothing untoward," said Ethan. "We use the cupboard because it's private."

"Only because we're all too scared to go in there!" said Robyn.

Cal sighed. "Okay. If you don't want to do it, we'll ask someone else."

"But you'd be perfect, Robyn," said Ethan. "No-one has their finger on the pulse like you do. Some might say you're the heartbeat of the ED."

Robyn shook her head sadly. "No. Charlie is the heartbeat of the ED."

"Then come along to the naughty cupboard – and you might be able to restart the ED's heart," said Cal.

An hour later, Robyn met Cal, Ethan and Lily in the naughty cupboard with a smile on her face. Ethan had had a rest (and, Cal suspected, a nap) in the staff room and looked a bit less pressured.

"I don't need to ask you if it went well," said Cal. "I can tell from the look on your beautiful face."

Robyn blushed, and smiled even more.

"With all your experience, Dr Knight," said Lily, "I'm surprised you can't come up with a better line than that."

Cal was hurt. "What was wrong with it? It worked, didn't it? Okay, Robyn. The floor is yours."

"Don't worry. I'm sure that's not an invitation to lie on it with him," said Ethan.

"It had better not be," said Robyn, but she was smiling too much to be completely convincing.

Cal smiled back.

"Robyn?" said Lily, when Robyn had stared at Cal and said nothing for several seconds.

"Oh, um, sorry," said Robyn. "I went up to the dispensary like you said. I know one of the dispensers quite well: I've seen her at the pub a few times. She's always up for a gossip."

"Which dispenser is that?" said Cal.

Robyn smiled. "She's called Robyn, actually!"

"Oh, yeah," said Cal, with a smile. "I know Robyn. Intimately."

"Yeah, she was saying you never went up there anymore," said Robyn.

Cal smirked in satisfaction.

"Though only because I mentioned you specifically," said Robyn. "I think she was quite glad you don't."

It was Ethan who smiled then.

"Anyway, I asked her what you told me," said Robyn. "And she says the only doctor who regularly visits the dispensary in person is you, Ethan."

Cal raised an eyebrow. "Oh, yeah, Nibbles?"

"She's seen Elle two or three times and Lily was up there recently too – first time she'd seen you for ages, Lily - but she hasn't seen Cal, Dylan or Mrs Beauchamp for months," said Robyn.

"It's possible they went up when she wasn't working," said Lily.

"No: she checked on the computer and everything," said Robyn. "It's all logged."

"What about the nurses?" said Cal.

"Oh, they all go up there except Rita, Charlie and David," said Robyn. "I suppose David's too shy and Rita and Charlie are too important. Big Mac goes up there the most often out of the HCAs."

Cal's eyes met Ethan's. "If David's never been to the dispensary, it can't be him."

"He could have taken it from a trolley – but everything we've heard about David shows he isn't maximising his opportunities," said Ethan. "It's not proof of innocence, but it is suggestive. Anyone who'd steal from a relative clearly grabs their opportunities. The psychology is wrong."

"What about Louise?" said Cal, once he'd finished rolling his eyes at Ethan's detective talk.

"She goes up quite a lot," said Robyn. "So does Jacob." She started to look worried. "You don't mean you suspect Louise?"

"We… we haven't ruled her out yet," said Ethan. "I don't suppose it is her, but we can't rule anyone out until we have evidence."

"Oh, no, I suppose not," said Robyn. "But I'm sure it's not Louise. Or David. Or Max obviously. Or anyone really."

"Thanks, for your help, Robyn," said Cal, smiling. "You've helped us a lot."

Robyn smiled nervously. "So, do you suspect me?"

"Not of stealing tramadol," said Cal. "Stealing hearts is another matter."

Cal gave Elle his most winning smile. "Elle. We need a favour."

"That sounds ominous," said Elle.

"You know the incident recently where one guy stuck a pair of scissors in another guy's leg?"

Elle nodded. "Yes, that one did stick in my mind. A dramatic day even by our standards."

"We were wondering who else was involved in the care of the two patients," said Cal.

"Ah. For your investigation," said Elle. Her eyes shone with amusement, but her face was otherwise calm.

"That's right," said Cal. "Or, to put it another way, were Lily, Jacob, Louise, David or Big Mac involved?"

Elle thought for a moment. "None of them were involved directly. Big Mac was checking obs when the scissors fell out of the patient's leg. I asked David to help, but he said he knew the family and thought it better not to get involved. Louise was there at the beginning, but she wasn't involved in the treatment – I think I asked her to get someone for me. Who were the others? Lily and Jacob? I remember Lily coming into Resus and asking for you, Ethan, which I thought was a bit odd, but that might have been another day."