John and Giulia stare at each other for a long instant, then as if drawn by an invisible force, they simultaneously turn their heads to look at the timer: still three missing pieces and less than 20 minutes left.
Giulia shuts her eyes for a second and turns her back to the screen, focusing on the table. She skims through the pictures and documents and spends a few seconds deep in thought, then says, "There's one person we haven't considered yet."
At that moment, Sherlock comes back to life with a jolt and looks at her, dazed. "Who?"
John cocks a brow at his awakening from his trance. "Are you back with us?"
Holmes throws him a grave look and turns his eyes around the room. "It's not like I can leave." He uses sarcasm to drag his brain back to mental alertness.
"Not sure about that. Your mind was somewhere else entirely," John points out.
"And now it's here. Who, erm, who did we miss?" he asks Giulia, trying to mask the shroud of uncertainty still enwrapping him.
"Oliver Portland, the dead man."
"I can't believe I have to say it, but the victim didn't do it, Giulia," Sherlock patronises her. "We can safely exclude suicide. He could have chosen among several interesting options, including jumping on the train tracks or a noose around the neck. But I've never seen anyone kill themselves by taking a swing at the back of their own skull."
She glares at him. Did he regain his full faculties just to talk down to her?
"I meant that we haven't considered what he had been doing in the moments before his death," she specifies.
"Oh right."
John chimes in, "We can see his working tools near the radiator in his bedroom. Considering he was quarrelling with his landlady over the malfunctioning of the house heating system, we could assume he tried to repair it himself during the day, maybe right after the fight with his mysterious guest in the afternoon. Manual labour is a good way to blow off some steam."
Sherlock nods. "Fair point. What else?"
Giulia takes over. "We know that at some point after the concierge's delivery at 7 pm, he took the Xanax. There is a missing tablet in the blister pack."
Sherlock gives them a proud look. "Look at you two: I should hand over the reins to you more often."
John glowers at him. His meltdown was no joke. They can't afford to lose him again.
Watson follows Giulia's train of thought. "What did he write on the pharmacy list? A remedy against dizziness and tachycardia, right? Must have been one hell of an argument if he needed to take Xanax after that."
Sherlock joins in. "Jim mentioned that Oliver Portland was behaving erratically lately, being uncharacteristically irritable, so maybe he was suffering from an anxiety disorder, or maybe he was just under a lot of pressure and stress for the upcoming astronomic exhibition. He took the pill after dinner and probably went to bed—after all, drowsiness is a common side effect of Xanax."
John frowns at that reconstruction of the events. "Went to bed?"
"Obviously. Look at the pictures: he must have been lying in bed right before dying. Observe the pattern on the sheets: there's the clear print of his body pressed against the mattress."
"Are you suggesting that the killer made him stand up, then hit him in the head?" Giulia sceptically asks.
"No, of course not. That would be ridiculous," Sherlock objects, but not even his arrogant tone can mask his confusion. It doesn't make sense. Oliver Portland was in bed, that much is clear. So how did he end up face-up on the soft carpeted floor with the back of his head caved in?
"Then how was he killed and by whom? We need to give Jim a name. Someone among the suspects must have killed him," John affirms.
"What if nobody killed him?" Giulia suggests, earning another condescending look from Sherlock.
"Again, stating the obvious here: there's always a killer involved in a murder."
For a second, she is tempted to slap him down off his high horse. Yet she knows he is going through a lot and has had a devastating breakdown, so she swaps violence for a more diplomatic and (despite Sherlock's remonstrance) entirely plausible theory.
"But what if this wasn't a murder? What if it was an accident?"
"The forensic team established he died from a blow to the head. How can that be accidental?" Sherlock counters.
"By falling and hitting the head, perhaps? We assumed it was murder based on the lethal wound, which, given the depth, indicated either a heavy object or a strong blow. What if it was both but the other way around? What if he fell and smashed his head hard on something with all his weight and the added force of gravity? Wouldn't it be possible?"
"Surely, but against what? That's why the incident option was never taken into account: there aren't any blood-stained blunt edges in his bedroom that would support your theory. His body was at the centre of the room, at the foot of his bed. If we assume he fell and hit his head, what did he fall against? There weren't any obstacles in his fall that would have smashed his head in. And there wasn't blood spatter on anything except the carpet and the dog's pawn prints."
"The dog!" Giulia exclaims. "What if the dog took away the object that killed him? He went by his side to look over his owner's body but maybe got distracted by an object, took it as a toy, brought it to the garden and buried it. That would explain why the police haven't found the 'murder weapon'—provided that we can still call it that way."
"It's a possibility," Sherlock confirms. "Especially considering the breed: Jack Russell Terriers have a high tendency to dig."
"How do you know?" John blurts out.
"I've always had a thing for dogs. Can we focus on the dead man's fate now?"
John brings his attention back to the case and skims through the copy of Dimmock's notes.
"Then how would the dog get to the garden if, as Dimmock noted down and Moriarty repeated, Rebecca Lockett found the bedroom door closed?"
"Through the dog flap," Giulia promptly replies, pointing at the French door to the garden in one of the bedroom's pictures.
"Fine. We'll get on board with your theory of the fall, then. So Mr Portland fell and smashed his head against something, like what?" John asks.
Sherlock's eyes glimmer at that question. "Like one of his tools, such as the hammer. Look at his toolbox. Where's the hammer? There's always a hammer in a toolbox."
John studies the pictures. "Okay good. We're getting closer." His tone harbours a bit more confidence, contrasting with the detective's gloomy expression. Something is still eluding him.
"Yeah, but falling down like that makes no sense. How did it happen? What was he doing?" Sherlock wonders. His eyes flit to the countdown: 15 minutes to go.
"Does it matter?"
"It does if we want to be absolutely certain of our answer," Sherlock retorts, stealing one more glance at the dark red curtain. They can't leave any stone unturned, not with his brother's life on the line.
He shifts his gaze to John. "We need to reconstruct what happened seconds before he died. So far, we can tell he went to bed and lay down for a while after taking the Xanax. Then he stood up for whatever reason. But why and how did he fall?"
"Maybe he just got thirsty or hungry?" John offers.
"He had eaten and drunk less than an hour and a half before. You can see on the kitchen table the rest of his dinner kindly delivered by the concierge."
"He had to use the bathroom, then? It's a universal law that the more you get comfortable in bed, the stronger the need to pee," Watson says.
Holmes waves one of the crime scene photos in front of John's face.
"The body is lying supine, meaning he fell to his back. You can easily imagine that when standing, he was facing the opposite direction of his en-suite bathroom door. Do you usually walk backwards into the bathroom?" he jibes.
"Fine. He was lying in bed: no late-night cravings, no urge to run to the toilet. Why did he stand then?"
Giulia chips in. "What if he got cold? That was the whole point of his arguments with his landlady, and Sherlock deduced that the mould on the walls demonstrated bad insulation. Maybe his room was freezing. It was freezing last night."
"Seems plausible. Perhaps he got up to turn the radiator on," John proposes.
"But he never got there," Sherlock interjects. "As you can see from the photos, the radiator dial is turned off."
"Alright, so he got up from the bed and was walking to the radiator when he stumbled and fell right onto the hammer, and Goodnight," Giulia strives to reconstruct the last instants of his life.
"Anyone that stumbles and loses their balance would grasp at things and toss something out or leave some trace on the ground, like a crease on the carpet. There are none of these signs around the body," Sherlock points out. "Besides, statistically speaking, someone walking is more likely to fall forward rather than backwards. But he did fall to his back because that's the position the body was found in, which was also the weird detail about the murder option."
That was the first thing he noticed and the first warning sign that things didn't add up.
"What happened, then?" John groans. "People don't just fall down without a reason. Did his brain get clouded?"
John's words have the same effect as a lightning strike on Sherlock's feverish mind. He looks to the glass capsule, then to the countdown on the screen, and a ghastly realisation slashes through the darkness of his doubt and confusion.
"Oh my God," he mumbles in shock.
John shoots him a perplexed look. "What?"
Holmes turns slowly around to face them, all colour drained from his face.
"Moriarty gave us forty-five minutes for a reason. Mycroft is trapped in that sealed tube. There are no holes, no vents, no breathers. When the countdown started, did you notice that a low, background buzzing sound suddenly stopped? It must have been the air circulation system inside the tiny capsule: Moriarty cut the oxygen. Calculating the volume of that cylinder and the toxic level of CO2 concentration, I'd estimate that Mycroft would last less than an hour before dying of hypercapnia—meaning abnormally elevated levels of carbon dioxide in the blood, as John would confirm."
The screen switches on to show a giddy Moriarty.
"You finally got it; the way I'm planning to take your brother's life. To tie in with the theme of this round, do you know what a big risk of death in space is, Sherlock? Absence of oxygen." He smiles cruelly.
The curtain is lifted off to show a pale, drowsy Mycroft. The violin music is still playing inside his crystal cage. Sherlock runs to the glass to examine his brother's condition: he is hyperventilating and appears disoriented and fatigued. His symptoms are consistent with hypercapnia.
John hobbles closer and asks, "How the hell did you get that?"
"Because it's the same principle behind Oliver Portland's death, except that it was carbon monoxide (and not dioxide) poisoning in his case."
"But the cause of death was blunt force trauma to the head," Watson protests.
"It was, but I'm sure the upcoming autopsy will also find life-threatening high levels of carbon monoxide in his blood. If he hadn't been so unlucky to pass out at that exact point and smash his head against the hammer he had left on the carpet, he would have died of carbon monoxide poisoning, which is the reason he fainted, rather than fell, when he stood up from the bed."
"How did he get carbon monoxide poisoning?" Giulia inquires.
"From the faulty central heating system. It can happen. Unluckily, there were no carbon monoxide detectors in the house, as you can see from the pictures, so he couldn't know he was slowly being poisoned."
John frowns. "Slowly? It took him less than two hours to faint."
"Yeah, but he had been exposed to low levels of carbon monoxide for quite some time. Clear neurological symptoms of long-term exposure were his frequent emotional changes, such as the fact he had recently become easily irritated, as reported by his closest friends. Yesterday, though, things took a turn for the worse, as proved by his request for a remedy against dizziness and tachycardia, yet another sign of intoxication. During the day, he tried to fix the heating system himself, fiddling with the radiator." Sherlock points at the tools in the pictures. "He might have been an expert astronomer, but not a very skilled manual worker, unfortunately. Unbeknownst to him, he tampered with the system, increasing the carbon monoxide leak in his bedroom. As we established, after having dinner in the kitchen and taking the Xanax, he went to bed. But he made one colossal mistake: he closed his bedroom door."
Giulia gives him a stunned look. "How do you know?"
"It's all in Dimmock's notes of the discovery of the body. The girlfriend specified that when she opened the door of the bedroom, she found him lying on the floor. Not only that, but she said she rushed out of the room and felt sick. I'm sure it was the shock of finding her boyfriend dead with his head smashed in, but I wouldn't exclude that the poisonous air contributed to her sense of nausea. All the windows were closed too, of course: as we said, it was a chilly night. With high levels of carbon monoxide in such an enclosed space, loss of consciousness may happen within two hours."
"That coincides with the estimated time of death," John confirms.
Giulia listens to the explanation, getting perplexed. "So he wasn't murdered then?"
Sherlock arches a brow at her. "It was actually your theory that he fell rather than being hit."
"I know, but if no one killed him, and it was an accident in the end, how are we going to solve this round? We are supposed to give Moriarty a killer."
Sherlock's eyes travel to the table and the photos of the suspects.
"He didn't ask for a killer. As always, his well-thought-out words are the key. He wants to know who the guilty party is."
"Isn't it the same thing?"
"Not in this case. As much as his death was accidental, it could have been prevented. The landlady didn't do the maintenance properly: she didn't intervene to fix the central heating system and didn't provide the flat with carbon monoxide detectors. Her negligence caused his death. She is the guilty party."
"Are you sure, Sherlock?" Moriarty taunts him from the screen. "Now you know what will happen if you give me the wrong answer: I won't restore the oxygen flux in Mycroft's little cage, and he will slowly die of asphyxiation under your eyes without you being able to do anything about it. How certain are you of your deductions? Are you ready to bet your brother's life on a case?"
Every word is a stab at both Sherlock's ego and heart.
Jim continues, "If I were you, before giving your final answer, I'd tell your brother all the things you never said. Call it a precautionary goodbye." And he switches off the violin music inside Mycroft's capsule.
Sherlock shoots one last glance at the timer: just a handful of minutes left now before the countdown reaches zero. Mycroft is running out of oxygen, and yet he is the one struggling to breathe. There's no more time. But maybe there was never a right time for the two of them.
Sherlock steps in front of the glass, his eyes fixed on Mycroft's face. He sighs, mustering the courage to speak.
"You have been a terrible big brother," he starts. "You said you tried to protect me, and I'm sure you believe it, but..." he pauses for a second, before adding, "But I wonder if you haven't just broken me beyond repair."
Mycroft doesn't react; he just listens silently.
Sherlock clenches his fists and can't stop the torrent of words and resentment gushing out of his mouth.
"But the absolute worst thing you instilled in me was a constant sense of inferiority to you. I don't even care that you've belittled my intelligence my entire life. I'm used to being bullied. But I hate that I'm always trying to prove myself to you. Because I'm never enough. Even now, you must think I'm not smart enough to solve the case. You must believe I'm sentencing you to death. I'll never be enough for you. Isn't it, Mycroft?"
He stares into his brother's eyes. "This is why I am a show-off. Because I never had your praise or a word of encouragement. And I go about my day impressing others because I could never impress you."
"Sherlock..." Giulia admonishes him. This is the worst time for taking all of this off his chest.
The detective steps away, turning his back to the glass.
"That's all I have to say to him."
Moriarty observes from the screen. "Let's see if your brother has some last words for you, then."
All the eyes in the room settle on Mycroft. He fights drowsiness and fatigue and sits up straight. He adjusts his shirt collar and tie, all the while staring at Sherlock. But he keeps silent. He just looks at his brother for seconds on end, then lowers his gaze without a word.
Moriarty tilts an eyebrow at that silent exchange. But John can't accept it.
"Mycroft, this might be the last time you see your brother. Is there nothing you want to tell him?" He tries to reason with him.
The elder Holmes shifts his eyes to Sherlock once more and silently holds his gaze, a serene expression on his face despite the situation.
He replies to John without taking his eyes off his sibling, "He knows what I think of him."
"Mycroft, come on," John begs.
Jim smiles almost tenderly from the screen and addresses Sherlock. "Isn't he cute when he doesn't understand something?"
And Giulia finally realises what he means: Mycroft is refusing to say his last words because he fully trusts Sherlock. He knows that his life is in his little brother's hands and doesn't believe he's about to die. Not with Sherlock on the case.
Sherlock takes a deep breath and faces the screen. With each passing minute, the air in the capsule gets more unbreathable. There's not a second to spare. It's time to solve the case.
"My solution to Oliver Portland's case is Mrs Edith Sheffield, the landlady. She is the guilty party."
As soon as he finished speaking, a whizz resounds from beyond the glass. Sherlock stares at his brother, hoping to see him respond to the incoming flow of oxygen, but to his surprise and utter horror, Mycroft's eyelids drop slowly as his body sags on the chair.
"Mycroft!" Sherlock shrieks, the anguish of his scream tearing through his ribcage. He runs to the tube, pounding on the glass. "Wake up, please, wake up!"
"What does it mean?" John yells at Moriarty. "Was it the wrong answer?"
"Dearie me. Did I forget to tell you that in case of the right answer, I would release a sleeping gas in his capsule? Oh well, that's exactly what just happened," Jim replies, seraphically.
Sherlock drops his fists and screws his eyes shut, pressing his forehead against the glass, panting. Mycroft is still alive. His brother will survive. He is safe.
"Don't worry, Sherlock. Your big brother will be alright," Jim cheers him up. "I just needed to put him to bed for a bit until we finish our game. He is now getting all the oxygen he needs; he'll recover soon. Then I will safely release him with all the other guests you've saved so far. Just a little more patience, dearest."
He types on his tablet and opens the automatic door of the room.
"Now, please collect yourself. It's time for a new challenge."