So far, so good.
"I do not see any security system," Jos whispered to Sammy, "but as I said, you mortals have such poor eyes. I can discern, though, that those," he nodded towards the fountain, "are not Cupids, but are in fact a somewhat obscure representation of the Angel of Death. Which makes their placement around that fountain a bit odd, since water is traditionally associated with life."
When the door opened and the somewhat confused guard peered out, Jos was already on him with the fast-talk. "Ah, kind sir, thank you again for letting my friend and I use your phone so that we may get ourselves out from this predicament. Also, my friend does have a very mighty need to use a restroom, so if you could to direct him, please, yes? Thank you!"
Shame I can't send Sammy a telepathic message to do a 'I Must Go Wee!' dance, it might help the act. Right, we overpower this guy, then find the main security room... wherever that is.