Prinzeps
"Remember, you've been given the opportunity to add your name to those helping in absolute cutting edge biological research. The advances made here will push industries forward at light speed - medicines can be tested without human risk! Nobody need lose family in wars ever again! Everything from organ shortages to labor shortages can be addressed. Even the entertainment industry is excited at what we do here - no need to risk stuntmen, or settle for 'almost' looks. The possibilities are endless.
"The project you've been assigned to is of great importance to national security. The final result will be able to infiltrate hostile areas and disable their ability to harm your countrymen, or rescue them before anyone realizes you're there. No need for signalling - they'll act as one...
"The hardest thing for some to remember, though, is that these are not humans. They look human, even react as human - they're designed to be able to interface and infiltrate that way. They will even simulate fear and pain. Just remember, that's all it is - a simulation."