ostinato indicates a part that repeats the same rhythm or melodic element
On a cold day in October, when Light is twelve, he comes home from school to find his father's car already in the driveway. He frowns at it as he goes inside.
His mother comes to the door to meet him, which is normal. She's frowning, which is not. Light greets her, and looks around for his father. There's no sign of him, except his shoes by the door, and no sound to indicate where he might be. "Is Dad in his study?" he asks, arranging his own shoes.
"Dad is upstairs resting," Sachiko says.
Light, who lives in well-concealed fear that someday his father will be injured in the course of his work, looks up a little bit too quickly. "Why? Is he hurt?"
"No, dear." Sachiko gives him a small smile that doesn't erase the worry in her expression. "He's sick, that's all. Let him rest for now, all right?"
"He's been sick before," Light says carefully. "And still gone to work, unless it was contagious."
"This is a different kind of sickness," says Sachiko, and Light grits his teeth at the simplistic explanation, but his frustration doesn't show on his face.
"Will he be here tomorrow?" he asks instead.
"He might." Sachiko looks at him a bit sadly. "Probably not the day after."
"Well," says Light with forced cheerfulness, "he can't be that sick if it only lasts two days."
Sachiko only smiles. It doesn't reach her eyes, and Light wishes he could take the words back.
Light doesn't expect Soichiro to come down to dinner, but he does. He seems much like his usual self, serious, but quick to praise Light and Sayu as they recount tales of the previous week. So quick to praise them, in fact, that Light wonders if he really hears any of what they're saying. Light watches his father throughout dinner, but there's nothing else to suggest he might be sick except the way he holds himself: gingerly, as though he's afraid of breaking.
After dinner, Sayu leaves to finish her homework and Soichiro retreats to his bedroom again, but Light stays in the kitchen with Sachiko.
"What's wrong with him?" he asks.
Sachiko sighs, and puts down the dish she's scrubbing. "It's just stress."
Light remembers reading about stress in a medical encyclopedia. Stress is the consequence of the failure to respond adequately to mental, emotional, or physical demands, whether actual or imagined. He knows there's more to it than that, of course, but the idea of his father failing to respond adequately to anything is strange and disturbing. "What are his symptoms?"
"Nausea. Dizziness." Despite her assurance a moment ago, Sachiko's face is grave. "Memory problems. And some chest pain."
Light nods. "I'm going to go read now," he says.
"All right." Sachiko pauses. "Don't worry about your father, dear. He'll be fine."
Light doesn't think she believes it.
In the sanctuary of his room, he curls up on his bed, The Art of War lying unopened beside him. He knows his reaction is based on a child's vision of a father, indestructible and powerful, and he's not a child anymore. Still, he's never had reason to doubt his father's strength before now, and he has to admit to himself that he's shaken by the idea that his father's noble work wears on him.
Well, he thinks, there's a first time for everything, and his father is only human.
And nothing, not even his father's health, is more important than the work he does. Right?
AUTHOR'S NOTE: It is the sort of thing that happens to you if you work in a stressful job all day, every day, over and over. Ostinato, yes? Incidentally, the quotation from the "medical encyclopedia" is actually from Wikipedia.