| Anna Torv | Olivia Dunham |
| Joshua Jackson | Peter Bishop |
| Jasika Nicole | Astrid Farnsworth |
| John Noble | Dr. Walter Bishop |
| Michael Cerveris | The Observer |
| Michael Kopsa | Captain Windmark |
| Blair Brown | Nina Sharp |
| Alexa Asjes | Nina's Assistant |
| Ian Butcher | Observer #1 |
| Mike Carpenter | Loyalist Guard #3 |
| Gabriel Carter | Loyalist Guard #5 |
| Jonathan Collins | Loyalist Guard #1 |
| Justin Doran | Loyalist Guard #2 |
| Shane Warren Jones | Loyalist Guard #4 |
| Gabe Khouth | Darryl Hastings |
| Rowan Longworth | Michael /
Child Observer |
| James Sullivan | Mr. Roe
(as James O'Sullivan) |
| Charles Edward Bae | Loyalist Scientist
(uncredited) |
| Ashley Whetung | Interrogated Employee
(uncredited) |