" Aunt Maxie giggled. ‘What can he be thinking about so hard?’
‘Best not to know,’ his mother said. She tsked. ‘One day that boy’ll go too far.’
‘Something serious. Look at him. He can’t even hear us talking about him. What can it be?’
‘Complex numbers,’ Garvie said, without taking his eyes off the table.
‘Oh.’
With a suspicious glance at her son, Garvie’s mother asked Aunt Maxie about the new locl convenience store, and they settled into a conversation about the scandalous rising prices of food.
Garvie carried on thinking.
a + bi, where i has the property i squared = -1. The product of a real number and an imaginary number. You don’t compute complex numbers, you rotate them. You move them into an imaginary dimension and the answer is an unexpected jolt from the blue.
‘Garvie? Garvie?’
He looked up at his aunt. ‘Alex is lying,’ he said. "

― Simon Mason , Running Girl (Garvie Smith Mystery, #1)