Albus" rumblings may have caused Scorpius" emotional outburst to subside a little, but something about it reveals a deeper, infinitely more tense layer of familiarity within him. The roots of Al's hot-tempered behaviour had been apparent before, sometimes even boiling over. In passing, Scorpius wonders how the air of darkness surrounding the man could have unsettled him to such an extent he hadn't seen before.