Four volunteers sign up for what initially appears to be a typical paid research study, only to discover that they've unwittingly become involved with a classified government program that was said to have been terminated nearly two decades ago.
| Actor | Role |
|---|---|
 Nick CannonPaul Brodie | Paul Brodie |
 Timothy HuttonCrawford Haines | Crawford Haines |
 Shea WhighamTony Mazzolla | Tony Mazzolla |
 Chloë SevignyMs. Reilly | Ms. Reilly |
 Peter StormareDr. Phillips | Dr. Phillips |
 Clea DuVallKerry Isalano | Kerry Isalano |
 Bill StinchcombCope | Cope |
 Meade PattonForsythe | Forsythe |
| MMichael ByrnesOrderly | Orderly |
 Gregory GastEcho | Echo |
| JJoan RobertsGod (voice) | God (voice) |
 Luke SextonOrderly #1 | Orderly #1 |
 Tim J. SmithOrderly #2 | Orderly #2 |