Greg spikes Ian's drink in Friday's Fair City on RTÉ One and the RTÉ Player.
Greg is determined to have his revenge after Ian deliberately got him drunk before an important meeting.
However, as Greg pours the powder into Ian's drink, Ian returns to the bar.
"What are you doing?" he asks Greg.
Watch what happens next on Friday on RTÉ One and the RTÉ Player at 7:30pm.
Fair City airs on RTÉ One and the RTÉ Player on Sundays, Tuesdays, Thursdays, and Fridays.
