A sandwich which whenever eaten, that pert that was eaten will grow back, regrowing the whole sandwich. if you tamper with the sandwich for too long, it will generate random food where a bite was taken. if tampered for even longer, it will generate random elements from the periodic table. the sandwich becomes safe to tamper with again when left alone for for ten hours. the guards outside the door are your bodyguards of sorts, and are there to make sure the tests go undisturbed.