"I'm so embarrassed," I whisper, tears inching down my face. "I'm sorry you had to see that." I look away from Spencer and drop my head onto the back of the couch.

"Actually, it's nothing to be ashamed of," Spencer starts, his voice raising half an octave to start the lesson. "Some research suggests as much as 13.2 percent of people have experienced a panic attack at some point in their lives." His lips spread into a straight line and he nods.

I blink at him. He never fails to teach me something, even in the midst of a crisis. I lean into him, my wet cheek pressed into his bony shoulder. He drapes thin, gentle arms around me and sighs.

"Talk to me about science, Spence," I say softly, my breath flicking his shirt's wrinkles. "Tell me about panic attacks."

Spencer traces an oval on my back with his finger. "Certain regions of the brain become hyperactive during a panic attack. Specifically, the amygdala, the fear center of the brain. When you're stressed, your sympathetic nervous system activates, then the parasympathetic nervous system comes in and calms you. If the parasympathetic nervous system fails, you'll stay in the state of hyperarousal and that results in the panic attack."

I look up at him. "So I'm not weak?" I ask, "It's just my brain?"

"Just your brain." Spencer nods. He runs his hand up into my hair and twists it around his fingers. He starts to breathe deeply, and I follow. He places the smallest of kisses on my head, and I manage to smile.

"You know," he whispers, "I've had a panic attack before."

I sit up and face him. "Really? When?"

He clears his throat and darts his eyes to the floor. He shifts uncomfortably and rubs his hands on his knees. "It happened in high school. I was in AP Physics and I saw someone who'd been bullying me out the window." He gulps. "He smiled and waved at me, and I just instantly felt so... scared. I got up and went to the bathroom, and that's when it happened."

I brush his cheek with my thumb. "How did it feel?"

"Horrible," he chokes out. "Like I was dying. I couldn't breathe. I felt my chest tighten, and my throat-" He stops. Spencer rubs his face with his hands. "Sorry, this isn't about me. I just want you to know you're not alone."

"Thank you, Spencer. Now I know that I'm not."

I hug him, and he hugs me back, hard. I laugh when my back cracks, and he giggles and apologizes. I playfully smack him on the shoulder, and he tackles me into the warmest embrace I've ever felt. We lay there, on the couch, holding each other, until we fall asleep.