At the officer's entreaty, the old man reached down in to his boot. Unknown to the officer, a second, identical flask was hidden there. In one, of course, was the medicine the old man had taken earlier. It was the second, however, which the old man retrieved now. "This?" he asked of the officer, unscrewing the top of the flask. "It's a rather nifty liquid, he said, and I think it better expressed in rhyme." Slowly, then, the old man tilted the flask of liquid over, spilling it on to the floor. As it poored, a devilish glint came in to his eyes, and he spoke.
"Though I know I should be wary,
still I venture someplace scary,
ghostly haunting I turn loose,
Beetlejuice, Beetlejuice, BEETLEJUICE!"
At this, the liquid seemed to take form. From the floor rose a nasty, ill-kempt dwarf of a man. He wore strange clothing and boasted shocking dental work, in addition to having a rather shocking head of hair. This newcomer turned to the old man, who had leapt to his feet.
"Beetlejuice, destroy this facility! Kill them all, in the name of our lord King Arthur!" It is perhaps unfortunate that Merlin's miscalculation was so grave. Beetlejuice did not care for having been bottled up like a genie for so many centuries by a crazed old fool, and now sought vengeance. He socked Merlin in the face, destroying his fragile bone structure and killing him instantly, and ran immediately to the nearest airlock by way of escape.
(Poor old codger probably should have just tried his luck with a fire spell.)