The quiet moments lie in wait to ambush him—when his mind has time to conjure intricate horror stories, to weave visions of doom from his doubts.
What if he's a Squib? Salazar... I'm half Muggle-half selkie, and Hermione is Muggle-born, so the odds must be astronomical. And so what if he's a Squib? Argus is a Squib, and he does just fine here at Hogwarts. It does not matter whether or not he has magical ability.
Severus twists his silver ring on his thumb absently, and his dark eyebrows draw together into a ferocious frown because he knows that it does matter to him—more than it should.
And what if he is magic, and then they find out what I am? What if they do not allow him a wand? What if he is persecuted because I am—"
"Gall!"
Severus launches up from the couch like an arrow, his wand whipped from its sheath before the echo of Syrena's screeched greeting dampens.
"English, Syrena," he admonishes as he forces his body to relax from its aggressive stance.
"I was using English first, but you were—" she flutters her fingers gracefully and rolls her black eyes, "—swimming in your thoughts."
Drowning in them, he thinks. Overwhelmed. Mired. Sinking. And then he really can't breathe properly for a black moment; it feels like his lungs are filled with lead and fear. He presses the bookshelf closed after Syrena exits the underground tunnel and rests his forehead against his hand, struggling to concentrate on calming his galloping heart, breathing tightly through residual panic.
"You are stressing too much," Syrena comments, stealing Hermione's favourite phrase.
"Nonsense." Severus aims a Drying Charm at her head before she reaches the couch; her tangled hair was wetly slicked back and dripping lake water onto the carpet.
She garbles her protest, flounces to the couch and flops down. "When you worry, Cass worries," she informs him with a little sniff.
Neptune be damned, the little brat has even picked up Hermione's bossy intonation. Severus rubs his temple and wonders how he's going to manage being a father without committing murder.
He deflects the focus of their conversation away from his obsessive concern and fretful brooding. "Did you tell your mother that you were coming up to the castle?"
Syrena sighs loudly. "Yes, Father Hen."
Severus scowls at her, silently berating her cheeky answer while he gauges the honesty of her answer, and then he gestures for her to move over and make room for him on the couch.
Syrena is wearing an old set of students' robes (she chose Gryffindor after being presented with the House characteristics, although Severus is certain that she has a Slytherin streak a mile wide), and at first glance she looks like any of his first-year students. But she's full-blood selkie—her skin has an eerie green tinge to it even after a vigorous Scourgify; her Airgead always sparkles at her wrist; her English is accented with an otherworldly, burbling lilt; she moves strangely in air, like all grace and coordination has bled from her limbs.
Syrena's slim hands starfish open and close, and a greedy light glints in her dark eyes. "Wand," she demands imperiously.
"Please..."
"Please." She drags the word out to at least three syllables.
Severus grimaces as he reaches into his robe pocket for his spare wand. "I honestly curse the day Hermione convinced me that we should teach you magic."
"But there's no harm in it," Syrena wheedles. "You're a selkie and you know Air Magic and—"
"Half-selkie. Besides, your mother and father would have an absolute conniption if they knew," Severus mutters.
"I won't tell them if you won't." Syrena flutters her long, inky eyelashes at him.
For a moment, Severus feels like he's standing on the edge of a cliff, and it feels like gravity and panic are pulling at him with long fingers. I would not want somebody going behind my back, teaching my child otherworldly things...
"Gall?"
His frown deepens. But would I deny my child the chance to learn and grow beyond what I have dreamed for him? Will I be as close-minded as Conn; imagine a box for my child before he's even born; ignore his most desperate dreams?
"Gall?"
He relents on the slope of a long sigh and hands her the wand; she leans head on his shoulder, gives him an enthusiastic, one-armed hug. After a moment and a half-smile, he shrugs her off and puts on his fiercest teaching expression. "Right. Let's see if you can cast an adequate Lumos today, shall we?"