Alec honestly has no idea how it started, but he knows how he found out about it.
"What do you mean the demon sneezed? How in Raziel's name does a demon sneeze?"
"Exactly what I said," Jace exclaimed, voice tinny through the phone's speakers. "If you have a better explanation, I'm all ears but that's the closest thing I can think of to describe it."
Alec sighed as he pinched the bridge of his nose. "Please tell me nothing got on you. The last thing we need is another demon pox."
"What do you think I am, an idiot? Of course, nothing got on me."
Alec's silence is deafening.
"You bastard," the blond replied, causing his parabatai to laugh. "Just for that, I'm telling Magnus."
"Go right ahead, he'll agree with me," he teased before getting back to business. "Report back to the Institute for a decontamination shower."
"Really Alec, a decontamination shower? Nothing got on me." Jace whined.
"Be grateful that it's just a shower and I'm not making you save your head, as per protocol."
"Alright, alright I'm on my way, no need to get your knickers in a twist."
~!~
"Okay, but how could a demon get sick in the first place?" Izzy pondered as she sat on the couch in the Head's office.
They were all gathered there, a few hours after Jace got back, to see if they could figure out how, when, where, and why a demon could get sick. And if it will lead to another epidemic.
"Oh, there are many ways, Isabelle," Magnus explained from where he was leaning against Alec's desk. "Stuck too close to the ley lines, a brush up against an angelic core, measles."
"Wait," Jace said trying and failing to hold back a laugh, "if demons can get human diseases, does that mean when Alec went out on patrol with a cold," the blond had to pause he was laughing too hard, "and sneezed on that demon." Jace couldn't finish his sentence but everyone knew where he was going.
Almost in unison, everyone turned to the aforementioned shadowhunter, who was blowing his nose due to said cold.
"What," he croaked, "I stopped going out on patrol."
"Yeah, after losing three separate arguments with Jace, Magnus, and I." Izzy quipped, earning a exasperated look from her brother.
Alec sent a pleading look not-so stealthily to Magnus.
"Alright, we figured it out, mystery solved. Back to work you two. I expect your reports on Alexander's desk," he cocked his head contempaltively, "first thing the day after tomorrow.'
"You're going to use this as a way to make sure that I take care of myself, aren't you?" Alec groaned out after his siblings left chuckling to themselves.
"Of course, darling. Wouldn't want you to ruin the career that you worked so hard on with the scandal of singlehandedly causing another demon virus." the warlock teased as he sat on the desk in front of Alec.
"And here I thought it was because you loved and cared about me."
"Perish the thought," Magnus smirked before pulling Alec in for a kiss.