Writer:	Tommy Thompson
Director:	Thomas J. Wright
Star:	Kevin Durand (Joshua (Season 2)),  J.C. MacKenzie (Reagan 'Normal' Ronald),  Martin Cummins (Ames White (Season 2)),  Valarie Rae Miller (Cynthia 'Original Cindy' McEachin (Season 1-2)),  Richard Gunn (Calvin 'Sketchy' Theodore),  Michael Weatherly (Logan Cale/Eyes Only),  Jessica Alba (Max Guevara "X5-452"),  Jensen Ackles (Alec "X5-494"/Ben (Season 2))
Guest Star:	Shawn Stewart (Bloody Fighter 1),  Deb Macatumpag (She-Beast),  Kimani Ray Smith (Bearded Homeless Guy),  Kyle Alisharan (Operative),  John Savage (Colonel Donald Michael Lydecker),  John Hainsworth (Skinny Homeless Guy),  Janet Wright (Annie The Announcer),  Rob LaBelle (Engel),  Jane Sowerby (Blue Collar Wife),  Brendan Beiser (Blue Collar Husband),  Vince Walker (Guy With Shotgun),  Nicholas Harrison (Cop 1),  Ashley Scott (Asha Barlowe),  John DeSantis (The Mangler Miller),  Ken Kirzinger (Bloody Fighter #2),  Shaker Paleja (Trooper),  Norman Armour (A Young Sandeman),  Brittany Cuevas (Young Max (6 Years Old)),  Stephen Aberle (Professor Long),  Ryan de Boer (X6-252),  Angela Uyeda (Cop 2)

This episode was nominated for the 2002 Excellence in Production Design Award for "Television - Episode of a Single-Camera Series". (edit)

Husband (taking dirty photos of his wife): Let’s get some shots of you vacuuming the sofa.
Wife: Okay. (turns on vacuum)
Husband: What are you turning that on for? Nobody’s gonna know the difference.
Wife: Yeah, but I might as well get it done, right? (edit) Max (questioning Husband): You don’t know anything about genetic enhancement?
Wife (as she grabs her chest): He got me these. (edit) Tech: Mind my asking how you ended up with one of these pop guns attached to your brain stem?
Max: Because he’s a cold-blooded, opportunistic showoff who thought he could run his game on a major bad guy who, it turns out, is an even bigger scumbag than he is. That about cover it?
Alec: Yeah, that’s pretty much how it happened. (edit) Tech (to Alec): Congratulations. You’re not dead. (edit) Tech: I can disarm it. It'll cost you ten grand.
Max: That the only number you know? (edit)

TRIVIA: Joshua is the only Manticore creation who doesn’t have a barcode, because he was the first transgenic created by Sandeman. (edit) TRIVIA: Jensen Ackles and Martin Cummings will star together again, as enemies, in the 2005 horror movie "Devour". Jensen is the leading character, Jake Grey, while Martin is one of the bad guys. (edit) TRIVIA: This is the final appearance by John Savage (Colonel Lydecker) for the rest of the series. (edit)

Title: Proof Of Purchase

This is a reference to when Alec has to bring back barcodes of transgenics, to prove he's killed them, and also a reference to when people cut out barcodes to provide proof of purchase to manufacturers.
(edit)