saint florian's abbey, begun in 1689, is the work of an italian and an austrian-- carlo carlone and jakobrandtauer. in true baroque fashion, the new abbey was a stage upon which royal ritual could be played out by the visiting emperor. paradoxically, the stage usually lacked its leading actor, for the emperor himself rarely visited any of the abbeys. but it didn't matter. the object was not imperial housing. it was to make a political point, to bear witness to the unity of christianity and empire. here we're dealing not with the glorification of an individual emperor, but with the need to assert the divine right to rule of an institution, the hapsburg empire. newly victorious over the turks, the austrians believed themselves to be the saviors of christian europe. they proclaimed their triumph in their art and in their architecture. the karlskirche, or charles church, in vienna, is an example of the power of the christian faith to absorb and transfigure many influences. the gabled portico reminds us of the pantheon. the columns suggest trajan's column in imperial rome as well as the bible'

. >> kroft: it was the suspicious death of a roman catholic priest named florian gall that set in motionnts that would eventually expose charles cullen. reverend gall had died unexpectedly overnight while recovering from pneumonia, and the hospital discovered high levels of the heart drug digoxin in his blood. it was the second unexplained overdose in two weeks. >> dr. marcus: the blood levels were astronomical. they were way higher than you would ever shoot for by using the drug therapeutically. >> kroft: dr. steven marcus is the director of new jersey's poison control center. he heard about the digoxin overdoses when a pharmacist at somerset called his office asking for help with some dosage calculations. the pharmacist also confided that two more patients in the same unit had turned up with abnormally high levels of insulin. what's going through your mind? >> dr. marcus: my number one, two and three thought was that there was something malicious going on in the institution. >> kroft: in july of 2003, marcus set up an urgent conference call with the hospital's medical director, dr. wil