Lucas Caleb Rooney (Matty Cullen) previously played the role of Lawrence in Episode 2.18, Legion (2003).
John Rue has played four different roles over the course of the series:
- Harry Mulrooney in Episode 8.11, Lady's Man (2009)
- Mr. Taylor in Episode 6.13, Albatross (2007)
- Quizmaster in Episode 4.19, Beast (2005)
- Thomas Findel in Episode 3.18, Ill-Bred (2004)