Zacharias had one of the magical journals as well - and an owl, of course. So Merlin would not be difficult to reach.
"Well then," he murmured, his lips curving upwards into a little smirk of a grin. "I'll be in touch soon, Merlin Toke," he said, and he started walking again, brushing against the other as he passed, and casting him another little grin before he walked off.