Allergens (substances that cause allergies) stimulate the body to release chemicals. These chemicals cause inflammation. If this inflammation causes the skin to swell, the condition is called angioedema. Angioedema is similar to hives, but it occurs deeper in the skin.

Allergic angioedema may be triggered by allergies to foods, drugs, latex, or insect stings. It also occurs in children with an infection or autoimmune disorders. Although it is rare, some children have a form of angioedema that is inherited.

Angioedema occurs suddenly, within minutes to hours after exposure to an allergen. Swelling usually appears on the face, lips, mouth, throat, arms and legs, or genitals. The swelling is patchy and asymmetrical. The skin will be red. Hives may also develop. The areas are usually painful and warm, but not itchy. The swelling goes away in a day or two without leaving any marks. In some cases, angioedema can affect the bowels and cause colicky abdominal pain. The throat and airways in the lungs can also become swollen, causing difficulty breathing.

Mild symptoms go away on their own and do not require treatment. Moderate symptoms may be treated with antihistamines and corticosteroids to stop itching and swelling. Abdominal pain may be treated with pain medications. Severe symptoms, such as a swollen throat, are a medical emergency. To help a child who is having trouble breathing, certain invasive procedures may be done to ensure that the child is able to breathe.

"So, what do you think about all of this?"

The voices were echoing, bouncing off the white smooth walls of the morgue.

"Four ideas, so far…"

"Such as?"

There was the rustling of a notebook pages, then the sound of a pen being clicked.

"…which I'm not going to share with your lot until I see the toxicology and autopsy reports…"

"But, Sherlock!..."

"…on each of the five victims, Lestrade. This conversation is over."

The DI sighed with exasperation.

"Fine."

"O, please, spare me your dramatics," the detective pulled the latex gloves off and, without even looking, trust them in John's direction; the good doctor, who stood behind his back, barely had the time to snatch them before they ended up on the floor. "This wouldn't have happened, if you bothered to come sooner. So let's hear what the Scotland Yard managed to find out. Any leads?"

"How about getting out of here first, Sherlock?" Lestrade shuddered involuntarily. "I… can't… I don't want to talk about that here."

"Why?" Sherlock surveyed the bodies on the tables absentmindedly.

"Why? WHY?" Lestrade finally had enough. "For God's sake, Sherlock, they are kids!"

The sound of a door slamming shut sounded like a gunshot, shuttering the silence and sending echoes to bounce of walls once again.

John Watson looked at his friend reproachfully.

"What?" the detective snapped. "Have I said something wrong?"

The doctor just sighed and shook his head.

This was Sherlock, after all; what did he expect?

Especially now, when the detective, like a pure-bred hound sensing a trail, was ready to rush forward without hesitation, ignoring everything that was irrelevant, distracting or threatened to come between him and his goal.

The game was on.

And the most terrible thing was that this time there were lives of the innocent children at stake.

"Come on, John," Sherlock felt uncomfortable under his friend's reproachful gaze, although, for the life of him, couldn't find any logical explanation for this fact. "We need to find out what information Lestrade has. Hopefully, his emotional outburst…"

"Sherlock. Shut up," John snapped good-naturedly, pulling the door of the morgue open.

"But…"

"Just shut up."

They found Lestrade outside – leaning against his car and smoking. He was blowing the smoke out slowly, and his eyes were half-closed – seemingly a picture of content, if you don't count the pose. Rigid stance, a hand, balled into a fist and hidden inside the pocket of his unbuttoned raincoat – the DI looked as a taut spring.

A thick folder with the case papers was laid out on a bonnet of the car, and, noticing Sherlock, Lestrade nodded towards it, showing clearly his disinclination to talk. But Holmes at the moment wasn't keen on talking either – he always preferred case reports and documented witness' statements to, as he labeled it, "meaningless chatting".

Especially when aforementioned chatting had those unnecessary human emotions added to it.

John looked at frowning and engrossed in the papers Sherlock, then shifted his gaze to Lestrade.

"Well…"

"Autopsy and toxicology reports on all previous victims are in the folder, the fifth will be ready in the evening…" the DI stubbed out his cigarette and now, instead of throwing it away, was looking at it absently.

"This is not what I was about, Greg," John waved his hand dismissively, scrutinizing the grayish tint of his friend's face. "You smoke? Since when?"

"… he's been smoking since his teenage years," Sherlock piped in automatically, not raising his eyes from the papers and therefore missing Lestrade's deepening frown. "There's a Zippo lighter on the table in his office. With a quite sentimental engraving "To dearest Greg from Phoebe" and a date. Must've been important date for the girl – and for our inspector too, of course, if he's keeping the lighter. Sentiments, obviously. But he doesn't keep it at home, which could mean either his wife is unaware of her husband's smoking habit, or she doesn't approve Lestrade's seemingly romantic attachment to aforementioned Phoebe. From my point of view, both reasons are valid, by the way. The rest is just a simple calculation, which gives us the exact age when the inspector received that lighter…"

"… how did you...?" Lestrade looked at the detective in astonishment, and Sherlock finally deemed necessary to raise his gaze.

"You're always twiddling it when you're nervious."

This simple statement brought a smile first to John's lips, then to Lestrade's.

It wasn't logical at all, but Sherlock felt he had done the right thing this time. He smiled awkwardly with the corners of his lips – a small contribution to the overall mood – and focused his attention on the papers once again.

"Technically, I quit smoking several years ago," Greg sighed and with a well-aimed flick sent the remains of his cigarette into a nearest rubbish bin. "It's just… this case…"

"What's with it? It's not like it's your first time…"

"One of the victims is my niece, John."

The silence was deafening.