How would you explain the last sentence? Strike returned to the bar to buy a third pint. Back at his table beneath the cupola, he drew out his mobile phone and called a friend in the Metropolitan Police whose friendship, though of only a few years’ duration, had been forged under exceptional conditions. Just as Charlotte was the only person to call him “Bluey,” so Detective Inspector Richard Anstis was the only person to call Strike “Mystic Bob,” which name he bellowed at the sound of his friend’s voice. How would you explain the last sentence: he bellowed at the sound of his friend’s voice? Thanks!