It was definitely not his imagination. Gabriel didn’t do ‘just his imagination’. There was always a cause, even if he, irritatingly, couldn’t see what it was at first glance. (Made even more irritating because he ought to have been able to.)

His slow scan of the buildings caught the movement and his eyes snapped to the location, even after the man had vanished again. Gabriel didn’t try to squint for him, or otherwise indicate how well (or badly) he could see the other man; instead he just rolled his eyes. A phantom watcher? So boring. Gabriel could’ve done so much better, if he’d wanted to. He lifted his hand and waggled his fingers in a mocking, ‘I see you there’ fashion, wearing a smile to match.